In two types of brass, the ratios of Copper to Zinc are 4:1, and 3:7 respectively. If the two types of brass are melted and mixed in the ratio 3:2 a new type of brass is obtained. Find the ratio of Copper to Zinc in this new type of brass.

Type 1 brass: Copper:Zinc = 4:1. For 3 units of Type 1, copper = 3 × 4 = 12 units, zinc = 3 × 1 = 3 units. Type 2 brass: Copper:Zinc = 3:7. For 2 units of Type 2, copper = 2 × 3 = 6 units, zinc = 2 × 7 = 14 units. When mixed: Total copper = 12 + 6 = 18 units. Total zinc = 3 + 14 = 17 units. Ratio Copper:Zinc = 18:17. Hmm, this doesn't match option B (3:2). Let me reconsider. Actually, the two types are mixed in ratio 3:2. This means we take 3 parts of Type 1 and 2 parts of Type 2, where each part is the same quantity. Type 1 (4:1) means 4 parts copper, 1 part zinc, total 5 parts. Type 2 (3:7) means 3 parts copper, 7 parts zinc, total 10 parts. When we take 3 parts of Type 1 and 2 parts of Type 2, we need to ensure we're comparing like quantities. Let's say 1 part = x units. Then 3 parts of Type 1 = 3x units total, containing (4/5) × 3x = 12x/5 copper and (1/5) × 3x = 3x/5 zinc. 2 parts of Type 2 = 2x units total, containing (3/10) × 2x = 6x/10 = 3x/5 copper and (7/10) × 2x = 14x/10 = 7x/5 zinc. Total copper = 12x/5 + 3x/5 = 15x/5 = 3x. Total zinc = 3x/5 + 7x/5 = 10x/5 = 2x. Ratio Copper:Zinc = 3x : 2x = 3:2. Option B is correct. Options A, C, and D represent different ratios.