A company has 2 photocopy machines. The probability that machine a will break down on a given day is 2%. The probability that a machine b will break down is 2.5%. What is the probability that both machines will breakdown on a given day?

The two events have independent probabilities.

To get the probability of both of the events happening, you should multiply them:

2% (or 0.02) * 2.5% (or 0.025) = 0.0005 or 0.05%

The probability that both machines will break down on a given day is 0.05%.