Correct Answer - Option 2 : 3 kg

**Given:**

Total Quantity = 60 kg

Ratio of Gold and Copper = 8 : 7

**Calculation:**

Let the quantity of gold added be X kg.

G : C = 8 : 7

Where,

G = Quantity of Gold in the mixture

C = Quantity of Copper in the mixture

G = 8k

C = 7k

So,

⇒ 8k + 7k = 60

⇒ 15k = 60

⇒ k = 4

Now,

G = 8k

⇒ G = 32 kg

C = 7k

⇒ C = 28 kg

After then,

(G + X)/C = 5/4

⇒ (32 + X)/28 = 5/4

⇒ 128 + 4X = 140

⇒ 4X = 12

⇒ X = 3 kg

**∴ 3 kg of Gold should be added for becoming the ratio 4 : 3.**