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We have three alloys with different Copper to Zinc ratios:
• Alloy A: Cu:Zn = 1:2
• Alloy B: Cu:Zn = 2:3
• Alloy C: Cu:Zn = 1:4

These are mixed in the ratio 2:3:5. We need to find the final Cu:Zn ratio.

Step 1: Convert ratios to fractions
If Cu:Zn = a:b, then Copper fraction = a/(a+b)

• Alloy A (1:2): Copper = 1/3, Zinc = 2/3
• Alloy B (2:3): Copper = 2/5, Zinc = 3/5
• Alloy C (1:4): Copper = 1/5, Zinc = 4/5

Step 2: Calculate Copper contribution from each alloy
We take 2 parts of A, 3 parts of B, and 5 parts of C.

Copper from A = 2 × (1/3) = 2/3
Copper from B = 3 × (2/5) = 6/5
Copper from C = 5 × (1/5) = 1

Total Copper = 2/3 + 6/5 + 1

Finding common denominator (15):
= 10/15 + 18/15 + 15/15 = 43/15

Step 3: Calculate Zinc contribution from each alloy
Zinc from A = 2 × (2/3) = 4/3
Zinc from B = 3 × (3/5) = 9/5
Zinc from C = 5 × (4/5) = 4

Total Zinc = 4/3 + 9/5 + 4

Finding common denominator (15):
= 20/15 + 27/15 + 60/15 = 107/15

Step 4: Find the ratio
Cu : Zn = 43/15 : 107/15 = 43 : 107

Answer: C
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Three alloys - A, B, and C contain only Copper and Zinc in the ratio 1:2, 2:3, and 1:4 respectively. The three alloys are mixed in the ratio 2:3:5 to form a new alloy. What is the ratio of Copper and Zinc in the new alloy?

A. 29 : 61
B. 37:59
C. 43:107
D. 61:29
E. 107:43
Video explanation:
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