Question:
If $a,$ $b$ and $c$ are three (not necessarily different) numbers chosen randomly and with replacement from the set $\{1,2,3,4,5\},$ what is the probability that $ab+c$ is even?

Answer:
The quantity $ab+c$ is even if and only if $ab$ and $c$ are both odd or both even. The probability that $c$ is odd is $\frac{3}{5},$ and the probability that $ab$ is odd is $\left(\frac{3}{5}\right)^2 = \frac{9}{25}$ (because both $a$ and $b$ must be odd). Therefore, the probability that $ab+c$ is even is \[\frac{3}{5} \cdot \frac{9}{25} + \left(1 - \frac{3}{5}\right)\left(1 - \frac{9}{25}\right) = \boxed{\frac{59}{125}}.\]