A bag contains $n$ red and $3$ blue counters, where $n$ is a positive integer. Two counte

Question

A bag contains $n$ red and $3$ blue counters, where $n$ is a positive integer. Two counters are drawn without replacement. The probability that they have the same colour is $\frac25$. Find every possible value of $n$.

Accepted Answer

$n=2$ or $n=3$.

Probability

Probability

Solution:

Solution locked