An alloy of copper and nickel contains 65 copper A second alloy contains copper and nickel in the ra...........

Explanation:

First alloy – 65% copper. ∴ 35% Nickel.

Ratio is 65 : 35
⇒ 13 : 7. 2nd alloy – Ratio is 17 : 3

Proportion of copper in the 1st alloy = 13/20

and proportion of copper in the 2nd alloy = 17/20.
Also proportion of copper in resulting alloy = 4/5.

required ratio is (17/20 – 4/5) : (4/5 – 13/20) = 1 : 3.

hence, otpion 3 is the correct answer.