Civil Services Examination · Question 65
An alloy P contains 20% copper and 80% zinc by weight. Another alloy Q contains 60% copper and 40% zinc by weight. A third alloy R is to be prepared from P and Q so that it contains equal amount of copper and zinc. In what ratio, amounts of P and Q be mixed in order to get R?
Show answer & explanation
Answer: (A) 1 : 3
Explanation
Target 50% copper. By alligation, P : Q = (60 - 50) : (50 - 20) = 10 : 30 = 1 : 3.