Question

 Three given numbers, first is two times the second and second is two times the third. The average of three numbers is 21. The largest of the three numbers is
1. 32
2. 28
3. 36
4. 40

Answer 1

Correct Answer - Option 3 : 36

Given:

First is two times the second and second is two times the third.

The average of three numbers is 21.

Formula used:

Average = (Sum of total observations)/(Total number of observation)

Calculation:

Let the third number is 'x'.

Second number = 2x

First number = 2 × 2x = 4x

Average = (Sum of total observations)/(Total number of observation)

⇒ (Sum of total observations ) = Average × (Total number of observation)

⇒ The required sum = 21 × 3 = 63

Sum of three numbers = x + 2x + 4x = 7x

According to the question,

7x = 63

⇒ x = 9

So, the largest number is (9 × 4 = 36)

∴ The largest number is 36.