Question

A bottle contains 20 blue bags and 15 red bags. If two bags are picked at random one after the other with replacement, what is the probability that the first bag is blue and then red?

Answer 1

12÷49

Explanation:

The total number of bags in the bottle = 20 + 15 = 35

Then

the probability that the first bag is blue = 20/35

If we replace the first bag :

the probability that the second (picked) bag is blue = 15/35

Conclusion:

If two bags are picked at random one after the other with replacement

Then

the probability that the first bag is blue and then red is :

(20÷35)×(15÷35)

= (4÷7)×(3÷7)

= 12÷49

= 0.244897959184