13 and yes... I used a calculator.
45 minus 13 is 32.
negative 45
987654193
32 45
98765325
45
48 minus 32 is 16.
32 minus 15 is 17.
84 minus 32 is 52.
2,012 minus 32 is 1,980.
The answer you seek is.... 3 hours and 13 minutes !
It is: 32 minus 4 = 28