Please help and explain it would be very helpful

So for the first one think of it as decimals so it’s easier: 9.20-7.35, subtract and it would be 1.85 so since we use decimals to make it easier it isn’t actually a decimal so it would be 2 hours and 25 minutes. And for the second one you just add 50 minutes to that and you would get 3 hours and 15 minutes.

The decimal expansion would be .27 repeated