# Moderate Probability Solved QuestionAptitude Discussion

 Q. If the probability that $X$ will live 15 year is 7/8 and that $Y$ will live 15 years is 9/10, then what is the probability that both will live after 15 years?
 ✖ A. 1/20 ✔ B. 63/80 ✖ C. 1/5 ✖ D. None of these

Solution:
Option(B) is correct

Required probability

$=\dfrac{7}{8}\times \dfrac{9}{10}$

$=\dfrac{63}{80}$

## (2) Comment(s)

Suman
()

I AGREE with ravi ,the sample space is undefined ,therefore HOW can we decide the probability after 15 years

Ravi
()

The answer must be none of these.

The question asks the probability of both living after 15 years,

but the data given is probability of living upto 15 years