A bag of peanuts in their shells contains 178 peanuts. 78 of the shells contain one peanut, 95 of the shells contain two peanuts, and the rest contain three peanuts. Of the shells with one peanut, 19 of them are cracked. Of the shells with two peanuts, 25 of them are cracked. None of the shells with three peanuts are cracked. One peanut shell is randomly selected from the bag. What is the probability the shell is cracked?
We have 178 peanuts.....
We could either choose one of the 19 of one-shelled peanuts that were cracked or we could choose one of the 25 two-shelled peanuts that were cracked
So....
P ( chhosing one of the 19 cracked one-shelled peanuts or 25 of the 2 cracked two-shelled peanuts ) =
19/ 178 + 25 /178 =
44 / 178 =
22 / 89 ≈ 24.7 %