Question

In an alloy, the ratio of copper and zinc is 5:2. If 3.75 kg of zinc is mixed in 52 kg 500g of alloy, then the ratio of copper and zinc in the alloy will be:

• A. 1:2
• B. 2:3
• C. 3:2
• D. 2:1

Hint:

When adding a material to a mixture, recalculate the ratio by keeping the initial component unchanged and adjusting the added component.

Answer 1

The Correct Option is D

Given, the initial ratio of copper and zinc in the alloy is 5:2. Let the total weight of the alloy be \( 52 \, \text{kg} \, 500 \, \text{g} = 52.5 \, \text{kg} \). The copper and zinc are initially in the ratio 5:2, so: - The amount of copper in the alloy is: \[ \text{Copper} = \frac{5}{7} \times 52.5 = 37.5 \, \text{kg} \] - The amount of zinc in the alloy is: \[ \text{Zinc} = \frac{2}{7} \times 52.5 = 15 \, \text{kg} \] When 3.75 kg of zinc is added to the alloy, the new amount of zinc is: \[ \text{New Zinc} = 15 + 3.75 = 18.75 \, \text{kg} \] The amount of copper remains unchanged at 37.5 kg. Thus, the new ratio of copper to zinc is: \[ \text{New ratio} = \frac{37.5}{18.75} = 2:1 \]