Answer and Step-by-step explanation: For an exponential distribution, the probability distribution function is:
f(x) = λ.[tex]e^{-\lambda.x}[/tex]
and the cumulative distribution function, which describes the probability distribution of a random variable X, is:
F(x) = 1 - [tex]e^{-\lambda.x}[/tex]
(a) Probability of distance at most 100m, with λ = 0.0143:
F(100) = 1 - [tex]e^{-0.0143.100}[/tex]
F(100) = 0.76
Probability of distance at most 200:
F(200) = 1 - [tex]e^{-0.0143.200}[/tex]
F(200) = 0.94
Probability of distance between 100 and 200:
F(100≤X≤200) = F(200) - F(100)
F(100≤X≤200) = 0.94 - 0.76
F(100≤X≤200) = 0.18
(b) The mean, E(X), of a probability distribution is calculated by:
E(X) = [tex]\frac{1}{\lambda}[/tex]
E(X) = [tex]\frac{1}{0.0143}[/tex]
E(X) = 69.93
The standard deviation is the square root of variance,V(X), which is calculated by:
σ = [tex]\sqrt{\frac{1}{\lambda^{2}} }[/tex]
σ = [tex]\sqrt{\frac{1}{0.0143^{2}} }[/tex]
σ = 69.93
Distance exceeds the mean distance by more than 2σ:
P(X > 69.93+2.69.93) = P(X > 209.79)
P(X > 209.79) = 1 - P(X≤209.79)
P(X > 209.79) = 1 - F(209.79)
P(X > 209.79) = 1 - (1 - [tex]e^{-0.0143*209.79}[/tex])
P(X > 209.79) = 0.0503
(c) Median is a point that divides the value in half. For a probability distribution:
P(X≤m) = 0.5
[tex]\int\limits^m_0 f({x}) \, dx[/tex] = 0.5
[tex]\int\limits^m_0 {\lambda.e^{-\lambda.x}} \, dx[/tex] = 0.5
[tex]\lambda.\frac{e^{-\lambda.x}}{-\lambda}[/tex] = [tex]-e^{-\lambda.x} + e^{0}[/tex]
[tex]1 - e^{-\lambda.m}[/tex] = 0.5
[tex]-e^{-\lambda.m}[/tex] = - 0.5
ln([tex]e^{-0.0143.m}[/tex]) = ln(0.5)
-0.0143.m = - 0.0693
m = 48.46
If (5^4)m=5^12 What is the value of M
Answer:
Step-by-step explanation:
Easy way to solve
5^4 = 625.
5^12=244140625.
Thus, 625m=244140625.
Divide both sides by 625/
m=390625, or 5^8.
Better way to solve
When dividing by exponents [tex]x^{4}/x^{2} =x^{4-2}=x^2[/tex]
Thus, simply do 12-4=8 to know that m=5^8.
Hope it helps <3
Answer:
5⁸Step-by-step explanation:
(5⁴)m = 5¹²
Divide both sides by 5⁴
((5⁴)m)/5⁴ = 5¹²/5⁴
m = 5⁸
9 less than twice a number is 13. What is the number?
Answer:
11
Step-by-step explanation:
Answer:
x = 11.
Step-by-step explanation:
9 less than twice a number is the same thing as twice a number minus 9. Let's say that the number is x.
2x - 9 = 13
2x = 22
x = 11
Hope this helps!
Share £1200 in the ratio 3:5.
so you have the amount.
amount: 1200
then you have the ratio
ratio: 3:5
you have the count.
count: 2
and then you have the shares
shares: 8
and the amount per share is 150.00
so the total amount of shares is the sum of each person's ratio so,
so 1:5:2:3:9 = 1 + 5 + 2 + 3 +9 = 20 shares. hope that helps you..
write the statement for 4p = 8
Answer:
See below
Step-by-step explanation:
The statement that can be written for 4p = 8 is:
=> Four times a certain number equals eight.
what is the solution to the system of equations?
y = 4x-10
y=2
A) (3,2)
B) (2,3)
C) (-2,2)
D) (2,-2)
Answer:
A) (3, 2)
Step-by-step explanation:
y = 4x - 10
y = 2
Substitute y with 2 in the first equation and solve for x.
y = 4x - 10
2 = 4x - 10
12 = 4x
3 = x
Solution: x = 3, y = 2
Answer: A) (3, 2)
The Sugar Sweet Company is going to transport its sugar to market. It will cost $3500 to rent trucks, and it will cost an additional $150 for each ton of sugar transported. Let C represent the total cost (in dollars), and let S represent the amount of sugar (in tons) transported. Write an equation relating C to S. Then use this equation to find the total cost to transport 17 tons of sugar.
Answer:
C = 150S + 3,500.
$6,050.
Step-by-step explanation:
It costs $3,500 to rent the trucks, so your constant/y-intercept will be $3,500.
It will cost $150 for every ton of sugar, so your slope will be $150.
You then have your equation:
C = 150S + 3,500.
If you were to transport 17 tons of sugar...
C = 150 * 17 + 3,500
C = 2,550 + 3,500
C = $6,050.
Hope this helps!
Answer:
C = $6050
Equation:
To write the equation, we have to remember that C is the total cost, so that means the equation should end in "= C". S is the amount of sugar, so the equation would look something like this:
[tex]3500+150(S)=C[/tex]
3500 is at the beginning since that is the cost for the trucks, and each ton of sugar costs $150, and that would get multiplied by S amount of sugar, to get the total cost, C.
Solving the equation
To solve the equation when S = 17, we simply have to plug in S as 17 into our equation we wrote above.
[tex]3500+150(17)=C[/tex]
150 * 17 is 2550, and 3500 + 2550 is 6050, which is C.
C = $6050
WILL MARK BRAINLIST----- A particular map shows a scale of 1 cm:5 km. What would the map distance be (in cm) if the actual distance to be represented is 14 km?
Answer:
2.8 cm
Step-by-step explanation:
The map scale is 1 cm : 5 km. That means that 1 cm is equal to 5 km.
To find the map distance (in cm), we have to set up a ratio.
[tex]\frac{1 cm}{5 km} = \frac{x}{14 km}[/tex]
X (the map distance in cm) is over the actual distance of 14 km.
Now cross multiply and divide.
[tex]5x = 14[/tex]
[tex]\frac{5x}{5} = \frac{14}{5}[/tex]
[tex]x = 2.8 cm[/tex]
If the actual distance to be represented is 14 km, the map distance (in cm) will be 2.8 cm.
Hope that helps.
6th grade math , help me please :)
Answer:
a. 4.5 grams per cup
b. 3.2 ounces per week
c. 19.2 grams per cubic centimeters
d. $3.29 per gallon
Step-by-step explanation:
The unit rate is simply a ratio comparing 2 given quantities, whereby the denominator is 1.
The unit rate of the above given problems can be determined as shown below:
a. 18 grams of salt per 4 cups, to find the unit rate, calculate how many grams of salt you'd get in 1 cup by dividing 18 by 4
[tex] \frac{18}{4} = 4.5 [/tex]
Unit rate = 4.5 grams per cup
b. 19.2 ounces is gained by the baby in 6 weeks.
Unit rate is the amount of ounces gained in 1 week
Unit rate = [tex] \frac{19.2}{6} = 3.2 [/tex]
Unit rate = 3.2 ounces per week
c. Unit rate = [tex] \frac{76.8}{4} = 19.2 [/tex]
Unit rate = 19.2 grams per cubic centimeters
d. Unit rate = [tex] \frac{23.03}{7} = 3.23 [/tex]
Unit rate = $3.29 per gallon
Write the equation in slope intercept form for the line that passes through the point (0,-3) with slope -1/2.
Answer:
y = -1/2x - 3
Step-by-step explanation:
Slope-Intercept Form: y = mx + b
Step 1: Determine known variables
Slope = -1/2 (m = -1/2)
y-intercept - (0, -3), so b = -3
Step 2: Write in known variables
y = -1/2x - 3
Answer:
y = -1/2 - 3
Step-by-step explanation:
Well slope intercept is y = ax + b
ax is the slope which is given,
b is the y intercept which is -3 because the point (0,-3)
doesn’t have a x coordinate meaning if the line goes through that point it touches the y intercept at -3.
Thus,
the equation in slope-intercept is y = -1/2 - 3.
Hope this helps :)
The graph shows government receipts and outlays (both on-budget and off-budget) for . In what years did receipts appear to climb faster than outlays?
Answer: Receipts appear to climb faster than outlays in 2001, 2002, 2003 and 2004
Step-by-step explanation: So if you see the graph you can see that receipts started to climb faster by the middle of 2001 so in conclusion Receipts appear to climb faster than outlays in 2001, 2002, 2003 and 2004 hope that help you
When government revenues exceed government outlays in a particular year, this is called a d) budget surplus.
What is budget surplus?A budget surplus occurs when a government's income from taxes and other sources of revenue exceed its expenses and spending on public programs, services, and infrastructure. A budget surplus is a positive indicator for the government's financial health as it indicates that the government is able to manage its finances well, generate more revenue than it spends, and potentially pay off any debts.
Here, we have,
In contrast, a budget deficit occurs when government spending exceeds its revenue, resulting in increased debt and a potentially negative impact on the government's credit rating.
Budget surpluses can be used to invest in public projects or programs, reduce debt, or returned to taxpayers in the form of tax cuts.
However, it is important to note that budget surpluses can also be a result of reduced spending on public programs, which can have a negative impact on social services and infrastructure.
Therefore, the correct answer is d) budget surplus.
Learn more about budget surplus here:
brainly.com/question/30453443
#SPJ2
coomplete question:
When government revenues exceed government outlays in a particular year, this is called
A.
the national debt.
B.
a budget deficit.
C.
fiscal policy.
D.
a budget surplus.
Which system of equations represents the matrix shown below?
Answer:
c
Step-by-step explanation:
im not too sure
baby weights: a study was conducted to determin the average birth weight (in ounces) of babies born in hospitals in a five county area of a given state. A Simple Random Sample of Recent birth records at the local hospitals were selected and the confidence interval was calulated to be (117.89 ounces, 124.91), at a 95% level of confidence. Which statistic is appropriate for this confidences interval?
Answer: Sample mean [tex](\overline{x})[/tex]
Step-by-step explanation:
Given: A study was conducted to determine the average birth weight (in ounces) of babies born in hospitals in a five county area of a given state.
i.e. The parameter of the study is [tex]\mu[/tex] . (Population mean).
A Simple Random Sample of Recent birth records at the local hospitals were selected and the confidence interval was calculated to be (117.89 ounces, 124.91), at a 95% level of confidence.
Since a measure of sample is a statistic , and this case statistic is sample mean denoted by [tex]\overline{x}[/tex].
Hence, the statistic is appropriate for this confidences interval : [tex]\overline{x}[/tex]
g The equation for the change of position of a train starting at x = 0 m is given by The dimensions of b are Select one: a. L-1T-1 b. LT-1 c. T-3 d. LT-2 e. LT-3
Answer:
B. LT⁻¹Step-by-step explanation:
The question is incomplete. Here is the complete question,
The equation for the change of position of a train starting at x = 0 m is given by x =(1/2)at² + bt³. The dimensions of b are__
from the equation of motion given, the constant b is the velocity of the body. For us to get the dimension of b, we have to find the dimension of the velocity .
Since velocity is the rate of change of displacement of a body, then;
VELOCITY = DISPLACEMENT/TIME
displacement is measured in metres while time in seconds.
expressing the formula in terms of its fundamental unit,
v = metre/secs
Since the fundamental quantity of the metre is length (L) and that of seconds is the time (T); the dimensions is expressed as;
V = L/T
V = L * 1/T
V = L * T⁻¹
V = LT⁻¹
Hence the dimension of b is LT⁻¹.
Note that the dimension of a body is written in terms of its fundamental quantities.
The dimensions of b from the given equation are; B: LT⁻¹
Dimensional Analysis
The complete question is;
The equation for the change of position of a train starting at x = 0 m is given by x =(1/2)at² + bt³. The dimensions of b are__
Now, in that equation above, b represents the velocity of the motion. Now, the formula for velocity is;
Velocity = Distance/Time
Now, distance is also called Length and represented by L in basic parameters units while Time is represented by T.
Thus, the dimensions of b are; L/T or expressed as LT⁻¹
Read more on dimensional analysis at; https://brainly.com/question/1528136
If ABCD is a parallelogram, AD = 14, EC = 11, mZABC = 64°, mZDAC = 71°, and mZBDC = 25,
find each measure.
А
a) BC =
d) mZABD =
B
b) AC =
e) m ACD =
E
D
С
c) m DAB
f) mZADB =
Find attached to this answer the diagram of the Quadrilateral
Question:
If ABCD is a parallelogram, AD = 14, EC = 11, m∠ABC = 64°, m∠DAC = 71°, and m∠BDC = 25, find each measure.
a) BC =
b) AC =
c) m∠DAB =
d) m∠ABD =
e) m∠ACD =
f) m∠ADB =
Answer:
a) BC = 11
b) AC = 22
c) m∠DAB = 116°
d) m∠ABD = 39°
e) m∠ACD = 45°
f) m∠ADB = 25°
Step-by-step explanation:
a) BC
In the question above, EC = 11
We can see that EC and BC are equal sides of a diagonal line that has been divided into two equal parts in a Quadrilateral.
Hence, In a quadrilateral ABCD,
EC = BC
Hence BC = 11
b) AC
AC is one of the diagonal lines that divided parallelogram ABCD
AC = BC + EC
AC = 11 + 11
AC = 22
c) m∠DAB
m∠ABC = 64°
m∠ADC = 64°
For the two angles above, a diagonal bisects through those angles.
Also the sum of angles in a triangle = 180°
Hence,
180° = 1/2m∠ABC + 1/2m∠ADC +
m∠DAB
m∠DAB = 180° - ( 1/2 (64) + 1/2(64))
m∠DAB = 180 ° - 64°
m∠DAB = 116°
d) m∠ABD
Since,
m∠ABC = 64° and m∠BDC = 25
m∠ABC = m∠BDC + m∠ABD
64 = 25+ m∠ABD
m∠ABD = 64° - 25°
m∠ABD = 39°
e) m∠ACD
In the above question,
m∠ABC = 64°,
m∠ADC = m∠ABC, this is because, opposite angles in a quadrilateral are congruent and equal to each other.
Hence, m∠ADC = 64°
m∠DAC = 71°,
In a triangle , all the angles in a triangle = 180°
Hence,
180° = m∠DAC + m∠ADC + m∠ACD
180° = 71° + 64 ° + m∠ACD
m∠ACD = 180° -(71 + 64)°
m∠ACD = 180° - 135°
m∠ACD = 45°
f) m∠ADB
Since
m∠DAB = 116°
m∠ABD = 39°
The sum of angles in a triangle = 180°
180° = m∠ABD + m∠DAB + m∠ADB
180° = 39 ° + 116° + m∠ADB
m∠ADB = 180° - ( 116 + 39)°
m∠ADB = 25 °
a) BC = 11
b) AC = 22
c) m∠DAB = 116°
d) m∠ABD = 39°
e) m∠ACD = 45°
f) m∠ADB = 25°
Given : AD=14 , EC=11, m∠ABC= 64°, m∠DAC=71° and m∠BDC=25°
To find: BC =? , AC =? , m∠DAB =?, m∠ABD =? ,m∠ACD =? ,m∠ADB =?
Consider the figure given below ABCD is a parallelogram
To find a) BC
Given, EC = 11
As seen in figure that EC and BC are equal sides of a diagonal line that has been divided into two equal parts in a Parallelogram.
Hence, In a Parallelogram ABCD,
EC = BC
Hence BC = 11
To find b) AC
AC is one of the diagonal lines that divided parallelogram ABCD
AC = BC + EC
AC = 11 + 11
AC = 22
To find c) m∠DAB
Given, m∠ABC = 64°
m∠ADC = 64°
(For the two angles above, a diagonal bisects through those angles)
Also From Angle sum property;
Hence,
180° = 1/2m∠ABC + 1/2m∠ADC + m∠DAB
m∠DAB = 180° - ( 1/2 (64) + 1/2(64))
m∠DAB = 180 ° - 64°
m∠DAB = 116°
To find d) m∠ABD
Since,
m∠ABC = 64° and m∠BDC = 25
m∠ABC = m∠BDC + m∠ABD
64 = 25+ m∠ABD
m∠ABD = 64° - 25°
m∠ABD = 39°
To find e) m∠ACD
Given, m∠ABC = 64°;
m∠ADC = m∠ABC, this is because, opposite angles in a quadrilateral (here parallelogram) are congruent and equal to each other
Hence, m∠ADC = 64°
m∠DAC = 71°,
In a triangle , all the angles in a triangle = 180°(Angle sum property)
Hence,
180° = m∠DAC + m∠ADC + m∠ACD
180° = 71° + 64 ° + m∠ACD
m∠ACD = 180° - (71 + 64)°
m∠ACD = 180° - 135°
m∠ACD = 45°
To find f) m∠ADB
Since ,m∠DAB = 116° and m∠ABD = 39°
From Angle sum property;
180° = m∠ABD + m∠DAB + m∠ADB
180° = 39 ° + 116° + m∠ADB
m∠ADB = 180° - ( 116 + 39)°
m∠ADB = 25 °
Learn more:
https://brainly.com/question/23163052
Help please!!!!!!! Thxxxxx
Answer:
x= 155°
straight line equals 180°
since you have a side that equals to 25°
you subtract
180°-25° = 155°
Daniel's mom deposits $80 into his savings account for the year. Daniel decides to upgrade his game account which costs $7 per month. How many months will Daniel be able to pay for his game account if his mom doesn't deposit any more money into his savings account?
Answer:
11.43
Step-by-step explanation:
80÷7= 11.428571428571428571428571428571
i hope this helps
N
5. Use AABC to find the value of sin B.
A 7
B
25
B 24
C
24
А
C7
25
D 24
*see the attachment below for the missing figure
Answer:
[tex] sin B = \frac{24}{25} [/tex]
Step-by-step explanation:
Given a right angled triangle, ∆ABC
AB = 25
BC = 7
AC = 24
<ACB = 90°
Required:
Value of Sin B
Solution:
Using trigonometric ratio formula,
[tex] sin B = \frac{opposite}{hypotenuse} [/tex]
Opposite = AC = 24 (the side opposite to <B)
Hypotenuse = AB = 25 (the longest side facing the right angle)
[tex] sin B = \frac{24}{25} [/tex]
Solve for x: ( 1/2 )^(x−1)=2^(3x−4)
Answer:
[tex]\huge\boxed{x=\dfrac{5}{4}}[/tex]
Step-by-step explanation:
[tex]\left(\dfrac{1}{2}\right)^{x-1}=2^{3x-4}\qquad\text{use}\ a^{-1}=\dfrac{1}{a}\\\\\left(2^{-1}\right)^{x-1}=2^{3x-4}\qquad\text{use}\ (a^n)^m=a^{nm}\\\\2^{(-1)(x-1)}=2^{3x-4}\qquad\text{use the distributive property}:\ a(b+c)=ab+ac\\\\2^{(-1)(x)+(-1)(-1)}=2^{3x-4}\\\\2^{-x+1}=2^{3x-4}\iff-x+1=3x-4\qquad\text{subtract 1 from both sides}\\\\-x+1-1=3x-4-1\\\\-x=3x-5\qquad\text{subtract}\ 3x\ \text{from both sides}\\\\-x-3x=3x-3x-5\\\\-4x=-5\qquad\text{divide both sides by (-4)}[/tex]
[tex]\dfrac{-4x}{-4}=\dfrac{-5}{-4}\\\\x=\dfrac{5}{4}[/tex]
What is the equation of the line that passes through the point (3,6) and has a slope of 4/3
Answer:
y = 4/3x+2
Step-by-step explanation:
We can use the slope intercept form of the equation
y = mx+b
Where m is the slope and b is the y intercept
y= 4/3 x +b
Substitute the point into the equation
6 = 4/3(3) +b
6 = 4 +b
Subtract 4 from each side
2 = b
y = 4/3x+2
Solve x is less than or equal to 0 and x is greater than or equal to -4
Answer:
x = {-3, -2, -1, 0}
Step-by-step explanation:
x ≤ 0
x > -4
then
x {-3, -2, -1, 0}
(6/22 + 5/77) ^2 equalviant to in fraction form
Answer:
676/5929
Step-by-step explanation:
A fair die is rolled two times. What is the probability that both rolls are 6?
Answer:
1/36
Step-by-step explanation:
the fair die has 6 equal parts which means its the total
the probability of rolling a 6 is 1/6
the probability of rolling another 6 is 1/6
so u multiply 1/6 times 1/6 which is 1/36
hope this helps
Hey there
To make it perfectly clear, consider the sample space for rolling a die twice. There are 36 equally likely possible outcomes, 6 of which define the event "rolling the same number two times in a row". Then, the probability of this event occurring is 636, which is equal to 16.Hope this hopeCompute the mean and variance of the following probability distribution. (Round your answers to 2 decimal places.) x P(x) 6 0.10 12 0.35 18 0.25 24 0.30
Answer:
Mean = 16.5
Variance = 35.55
Step-by-step explanation:
x P(x) x. P(x) x² x². P(x)
6 0.10 0.6 36 3.6
12 0.35 4.2 144 50.4
18 0.25 4.5 324 81
24 0.30 7.2 576 172.8
∑x P (x) 16.5 ∑x² P (x) 307.8
The expected value of x E[X] gives the mean where X is the discrete random variable with the given probabilities.
Mean is given by E(X)= ∑x P (x) = 16.5
Similarly the variance is also calculated using the expected value of X and X².
Variance is given= E(X)²- [E(X)]²= 307.8- (16.5)²= 307.8-272.25 = 35.55
Write the Verbal phrases as an equation or an inequality? Use "x" as the variable?
Step-by-step explanation:
8.x×8-12=50
8x-12=50
9.1/2x>or=100
10.2 whole number5/9-x=31
which is true about the solution to the system of inequalities shown?
A) y ≥ 1/3x + 3 AND 3x - y > 2
B) y ≥ 1/2x + 3 AND 3x - y > 2
C) y ≥ 1/3x + 3 AND 3x + y > 2
D) y ≥ 1/3x + 3 AND 2x - y > 2
Answer:
the solution to the system of inequality is C
Cell phone bills for residents of have a mean of $47/line with a standard deviation of $9/line. Find the probability that the average cost/line for the Math
A paint manufacturer has a uniform annual demand for 16,000 cans of automobile primer. It costs $4 to store one can of paint for one year and $500 to set up the plan for production of the primer. Let x be the number of cans of paint produced during each production run, and let y be the number of production runs. Then the setup cost is 500y and the storage cost is 2.c, so the total storage and setup cost is C = 500y +2.c. Furthermore, .cy = 16,000 to account for the annual demand. How many times a year should the company produce this primer in order to minimize the total storage and setup costs?
A. The company should have 6 production runs each year.
B. The company should have 8 production runs each year.
C. The company should have 10 production runs each year.
D. The company should have 11 production runs each year.
Answer:
B. The company should have 8 production runs each year.
Step-by-step explanation:
From the given information:
A paint manufacturer has a uniform annual demand for 16,000 cans of automobile primer
It costs $4 to store one can of paint for one year
$500 to set up the plan for production of the primer
Let x be the number of cans of paint produced during each production run
Let y be the number of production runs.
If the total storage and setup cost is C = 500y + 2c
and cy = 16000
Then c = 16000/y
From;
C = 500y + 2c
Replacing c with 16000/y, we have;
C = 500y + 2(16000/y)
C = 500y + 32000/y
in order to minimize the total storage and setup costs [tex]C_{min} = C[/tex]
Therefore [tex]\dfrac{dc}{dy}=0[/tex]
⇒ 500 - 32000/y² =0
y² = 32000/500
y² = 320/5
y² = 64
y = (√64)
y = 8
Therefore; The company should have 8 production runs each year in order to minimize the total storage and setup costs
Given: AB=BC,AM=MC BM ⊥AC , EF⊥BC Prove: EC/AB = FC/MA
Answer:
90 degree EFC. and. BMC
across fc/ma
across ec/ab
Marcia is a bag that contains four green marbles, eight yellow marbles, and 20 red marbles. If she chooses one marble from the bag, what is the probability that the marble is not red?
Answer:
3/8
Step-by-step explanation:
The bag contains 4 green marbles, 8 yellow marbles and 20 red marbles.
The total number of marbles is 32.
She chooses one from the bag.
The probability of the marble not being red is:
P(not red) = 1 - P(red)
P(not red) = 1 - (20 / 32) = 1 - 5/8
P(not red) = 3/8
The probability of it not being red is 3/8.
Em uma prova de conhecimentos gerais, Fernando errou 3/8 do total de 72 questões. Quantas são as questões que Fernando ACERTOU?
Vamos lá.....
Duas maneiras praticas:
1 - Multiplicar a fraçao pelo total, vai informar quanto a fracao representa (o que é questionado na questao)
2 - Regra de 3.
1:
72 × (3/8)
216/8
27
Ele acertou 27 questoes
(pergunta mais que interessante: qntas questoes havia na prova??? 72)