Civil Service Exam Reviewer · Ratio and Proportion · hard
Alloy X contains gold and copper in the ratio 5 : 3; alloy Y contains them in the ratio 5 : 4. If equal weights of X and Y are melted together, what is the ratio of gold to copper in the new alloy?
- 85 : 59
- 10 : 7
- 59 : 85
- 25 : 12
Answer
A. 85 : 59
Solution
Take 72 units of each. Gold = 45 + 40 = 85; copper = 27 + 32 = 59. Ratio = 85 : 59.
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