To find the answer all you have to do is multiply each of the percentages by 3000.
57% clay
.57 × 3000 = 1,710 lb
39% silt
.39 × 3000 = 1,170 lb
4% sand
.04 × 3000 = 120 lb
Check your answer by adding the weights together. They should add up to 3000.
1710 + 1170 + 120 = 3000
It checks!