Question

An urn contains 5 red 10 black balls. Eight of them are placed an other urn .what is the chance that the latter then contains 2 red and 6 black balls

Answer 1

Let there be 2 boxes A & B.

A contains:

Red = 5

Black = 10  

Total = 15

Let 8 balls be transferred from A to B.

We need to find probability of B containing 2 red and 6 black balls.

Simply this can be solved by calculating possible no. of ways of selecting 2 red and 6 black balls out of 15 balls.

$\sf \large {=\frac{5c2 \times 10c6}{15c8}}$

= 0.326