Re: URGENT : Probability?

will not get an A in math means (it does not take math at all ) or (it takes math but not A)

So the probability is $\displaystyle \frac{1}{2}+\frac{1}{2}\frac{4}{5}$.

Re: URGENT : Probability?

Imagine 1000 Simrans. 500 of them take math, 500 of them take biology. Of the 500 who take math, 500(1/5)= 100 receive an A. That is, of the 1000 Simrans. 100 get an A in math and 900 do not. The probability Simran does not get an A in math is 900/1000. This is, of course, the same result Kmath got.