Question

A survey of the 12th grade students at Gaffigan High School found that 84% of the seniors have their driver’s licenses, 16% of seniors take the bus every day to school, and 14% of the seniors have driver’s licenses and take the bus to school every day.
To the nearest whole percent, what is the probability that a senior takes the bus to school every day, given that he or she has a driver’s license?

19%
17%
36%
70%

Answer 1

Use the formula for the conditional probability:

$Pr(A|B)=\dfrac{Pr(A\cap B)}{Pr B}.$

Consider such events

A - a senior takes the bus to school every day;

B -  a senior has a driver’s license,

then

$Pr(A\cap B)=0.14$,

$Pr(B)=0.84$

and

$Pr(A|B)=\dfrac{0.14}{0.84} =\dfrac{1}{6}\approx 0.16666.$

In percent this is nearly 17%.

Answer: correct choice is B.

Answer 2

Answer:

The answer is B for e2020

Step-by-step explanation: