Question

An alloy has iron, silver and bronze in the ratio 7 : 2 : 3. another alloy has silver and bronze in ratio 1 : 2. in what ratio should the two mixtures be mixed so that the ratio of iron and silver in resultant mixture is 5 : 3

Answer 1

Answer: 20:11

Explanation: Assume X kg of first alloy and Y kg of the second alloy is taken.

Amount of Iron in the first alloy = 7X/12 kg

The amount of Silver in the first alloy = 2X/12 kg

The amount of Silver in the second alloy = Y/3 kg

The ratio of Iron and Silver in the mixture is 5 : 3.

⇒ [(7X/12)/(2X/12 + Y/3)] = 5/3

⇒ [7X/(2X + 4Y)] = 5/3

⇒ 21X = 10X + 20Y

⇒ 11X = 20Y

⇒ X/Y = 20/11

Therefore, the ratio should be 20:11 if the ratio of iron and silver in the resultant mixture is 5:3.