Exams › SSC CGL (Prelims) › General

An alloy contains zinc and copper in the ratio 3:2. A second alloy contains zinc and copper in the ratio 4:1. What quantity of the first alloy must be mixed with 15 kg of the second alloy to produce a new alloy with zinc and copper in the ratio 13:7?

1. 25 kg
2. 35 kg
3. 45 kg
4. 50 kg

Correct answer: 45 kg

Solution

First alloy has zinc fraction 3/5 and copper fraction 2/5. Second alloy has zinc fraction 4/5 and copper fraction 1/5, and the final mixture must have zinc fraction 13/20. Let x kg be the first alloy. Then \(\frac{3x}{5}+12 = \frac{13}{20}(x+15)\), which gives x = 45.

Related SSC CGL (Prelims) General questions

• If \(a \% b = a^2 - b^2\) and \(a \% b = 63\), find \(a\) and \(b\).
• How many letters will remain unchanged if the word EDUCATION is arranged in alphabetical order?
• Select the letter cluster that will replace (?): B, F, J, N, R, V, Z, ?
• Pointing to a boy, a woman said, “He is the son of my father’s only daughter.” How is the boy related to the woman?
• If $4 \oplus 3 = 19$ and $5 \oplus 2 = 17$, then $6 \oplus 4 = ?$
• If $3x + 7 = 28$, find $x$.

⚔️ Practice SSC CGL (Prelims) General free + battle 1v1 →