1 1/2 hours
Time spent by Antonio in driving = 3 1/4 = 13/4
Time spent in gardening = 1 3/4 = 7/4
In order to find how much he spend driving than gardening, we can subtract 13/4 and 7/4.
13/4 - 7/4
Te denominator is same. So, we can directly subtract the numerators.
13-7/4
=6/4
= 3/2 = 1 1/2
Therefore, Antonio spent 1 1/2 hours more in driving than gardening.