Question

In a box, the ratio of red marbles to blue marbles is 7 : 4. Which of the following could be the total number of marbles in the box?

Options

• 18

• 19

• 21

• 22

Answer 1

22

Explanation:

Given, The ratio of red marbles to blue marbles = 7 : 4

Let the number of red marbles = 7x

And blue marbles = 4x

Then, total number of marbles = 7x + 4x = 11x

Total number of marbles must be multiple of 11.

By observation,

⇒ 11x = 11 × 2

∴ 11x = 22