If you want the total value paid you have to sum the three values.
Observe that:
8 and 3/8 = 8 + 3/8
12 and 1/8 = 12 + 1/8
15 and 3/8 = 15 + 3/8
The the sum is 8 + 3/8 + 12 + 1/8 + 15 + 3/8 = (8 + 12 + 15) + (3/8 + 1/8 + 3/8 ) = 35 + 7/8
So the total value was 35 and 7/8
