Question

A certain business school has 500 students, and the law school at the same university has 800 students. Among these students, there are 30 sibling pairs consisting of 1 business student and 1 law student. If 1 student is selected at random from each school, what is the probability that a sibling pair is selected?

Answer 1

3/40000

Explanation:

Data:

Business 500 students

Laws 800 students

30 pairs of siblings, 1 in each school

It is required to calculate the probability that a random pair of siblings is chosen.

For this:

Business, of 500 students we have 30 siblings to choose one

30/500

Continue, choose the sibling's partner, Laws, of 800 only 1 is the sibling of the chosen in Business.

1/800

So we have:

(30/500) * (1/800) = 30/400000 = 3/40000

You can choose in reverse, first Laws and then Business, leaving:

(30/800) * (1/500)= 30/400000 = 3/40000

And it gives the same result: 3/40000