Question

Zinc and copper are in the ratio 5 : 3 in 400 gm of an alloy. How much of copper (in grams) should be added to make the ratio 5 :4?

Answer 1

Zinc : Copper

5 : 3

Let 5x : 3x

Given, 5x + 3x = 400 g

8x = 400 g

x = 50 g

∴ Zinc : Copper

250 g : 150 g

Let a gram of copper is added

=> 250150+a=54

=> 1000 = 750 + 5a

=> 250 = 5a

a = 50 g

Answer 2

${\huge {\mathfrak {Answer :-}}}$

➡️ Zinc : Copper = 5 : 3.

Let, Copper = 3x and Zinc = 5x.

➡️ 3x + 5x = 400.

Or, x = 400/8 = 50.

➡️ Now, 3x = 150 g.

And 4x = 200 g.

➡️ Hence, amount of copper to be added is = 200 - 150 = 50 g.

That's it..