Question

Five days a week, from Monday to Friday, Betsy takes the bus to school. Each day she has a probability of 90% of taking bus 1. If she does not take bus 1 then she will take bus 2.

What is the probability that she will take bus 1 on all five days?

Answer 1

0.59

Explanation:

Given that :

Probability of taking bus 1

P(b1) = 90% = 0.9

What is the probability that she will take bus 1 on all five days?

Five days from Monday to friday:

On Monday : p(b1) = 0.9

On Tuesday : p(b1) = 0.9

On Wednesday : p(b1) = 0.9

On Thursday : p(b1) = 0.9

On Friday : p(b1) = 0.9

Here we have an independent event:

Hence, probability of taking bus 1 on all five days :

(0.9 * 0.9 * 0.9 * 0.9 * 0.9)

= 0.59049

= 0.59