Question

If the probability that a bird will lay an egg is 75%, the probability that the egg will hatch is 50%, and the probability that the chick will be eaten by a snake before it fledges is 20%, what is the probability that a parent will have progeny that survive to adulthood?

(A) 30%
(B) 14.5%
(C) 7.5%
(D) 2%

Answer 1

Answer: (A) 30%

Explanation:

Given : The probability that a bird will lay an egg =0.75

The probability that the egg will hatch =0.50

Now, the probability that the egg will lay an egg and hatch =
`0.75*0.50`

Also,The probability that the chick will be eaten by a snake before it fledges =0.20

Then, the probability that the chick will not be eaten by a snake before it fledges : 1-0.20=0.80

Now, the probability that a parent will have progeny that survive to adulthood will be :-

`0.75*0.50*0.80=0.30=30\%`

Hence, the probability that a parent will have progeny that survive to adulthood = 30%