Question

The ratio of number of men and women in a ice-cream factory of 840 workers is 5 : 7. How many more men should be joined to make the ratio 1 : 1?

• A. 240
• B. 200
• C. 190
• D. 140

Answer 1

Answer:

D. 140

Shortcut Trick

Men : Women = 5 : 7

Total number of workers = 840

⇒ The value of 12 → 840

⇒ The value of 1 → 70

Since more men are joining. But the women are the same. 

⇒ The value of 2 → 70 × 2 = 140

Alternate Method

Let the men and women in the ice-cream factory be 5x and 7x respectively.

⇒ 5x + 7x = 840

⇒ 12x = 840

⇒ x = 70

Thus, Men $=5x=5\times{70}=350$

And women $=7x=7\times{70}=490$

Let y more men should be joined to make the ratio 1 : 1.

$\frac{(350+y)}{490}=\frac{1}{1}$

⇒ 350 + y = 490

⇒ y = 140

Hence, 140 more men should be joined to make the ratio 1 : 1.