Question

Suppose a bus arrives at a bus stop every 35 minutes. If you arrive at a bus stop at a random time, what is the probability that you will have to wait at least 20 minutes for the bus?

A- 3/7
B- 1/2
C- 5/7
D- 3/4

Answer 1

5/7 because the original ratio would be 20/35 and then it would reduce to 5/7

Answer 2

`(3)/(7)`

Explanation:

Given : Suppose a bus arrives at a bus stop every 35 minutes

To Find: If you arrive at a bus stop at a random time, what is the probability that you will have to wait at least 20 minutes for the bus?

Solution:

A bus arrives at a bus stop every 35 minutes.

You arrive at a bus stop at a random time.

So, probability that you will wait at most 20 minutes =
`(20)/(35)`

So, The probability that you will wait at least 20 minutes =
`1-(20)/(35)`

=
`(35-20)/(35)`

=
`(15)/(35)`

=
`(3)/(7)`

Thus the probability that you will have to wait at least 20 minutes for the bus is
`(3)/(7)`