Question

The probability that a bridge structure needs rehabilitation after an earthquake of 6.9 intensity on Richter scale is 0.25. If it is considered for rehabilitation, the probability that it needs retrofitting is 0.40. If it does not need rehabilitation, the probability that it needs retrofitting is 0.14.

(1)        For any bridge structure, what is the probability that it does not need retrofitting?

(2)        For the bridge to be rehabilitated. What is the probability that it needs retrofitting?

Answer 1

Let

P(R) = 0.25

P(Re | R ) = 0.40

Where,

2) Here we want to find  the probability that it needs retrofitting given that the bridge to be rehabilitated.

That is P( Re | R ) = 0.40