Gabriel tosses a coin 60 times and has 32 heads

and 28 tails. We define a tails as a success.

What is the relative frequency of tails?

The relative frequency of an event is the ratio between how many times that event occurred and the total number of "experiments" performed.

In this case, you performed 60 "experiments", and 28 of them gave the desired output.

So, the relative frequency of tails is

7/50