122.5 kg

.

His total revenue is 108%, thus 175 * 1.08 = 175 * x * 1.05 + 175 * (1-x) * 1.15, with x being the fraction sold with 5% profit

1.08 - 1*1.15 = (1.05-1.15) * x => 0.07 = 0.1 * x

x = 0.7, thus the quantity sold with 5% profit is 0.7 * 175 = 122.5 kg