An alloy of tin and copper consists of 15 parts of tin and 105 parts of copper. Find the percentage of copper in the alloy?

85% 87.5% 82% 72%

87.5%

Number of parts of tin=15 Number of parts of copper =105 Total parts =15+105=120 ∴ Percentage of copper in the alloy = \(\frac{105}{120}\) × 100 = 87.5%