A bag contains $n$ red counters and $4$ blue counters. Two counters are selected without replace

Question

A bag contains $n$ red counters and $4$ blue counters. Two counters are selected without replacement. The probability that both are blue is $\frac{2}{15}$. Form an equation and find $n$. Find the probability that the selected counters have different colours.

Accepted Answer

(a) $n=6$; (b) $\frac{8}{15}$.

Probability

Probability

Solution:

Solution locked