If 140 g brass is mixed with copper to prepare an alloy having brass and copper in the ratio 4 : 3, then how much copper has been taken to prepare the alloy?

Correct option is A

Given:

140 g brass is mixed with copper to prepare an alloy having brass and copper in the ratio 4 : 3

Solution:

The ratio of brass to copper is 4:3. This means that brass makes up 4 parts out of a total of 4 + 3 = 7 parts.

Calculate the weight of one part:

140g of brass represents 4 parts. So, one part weighs 140g $$\div$$​ 4 = 35g.

Calculate the weight of copper:

Copper makes up 3 parts. Therefore, the weight of copper is 3 $$\times$$​ 35g = 105g.

Option (a) is right.