Question

When x is added each of 10, 23, 15 and 33, the sums obtained in this order are in proportion. The value of (x + 5) is:
1. 1
2. 8
3. 3
4. 5

Answer 1

Correct Answer - Option 2 : 8

Given:

The numbers are 10, 23, 15, and 33

x is added to each number and the sum is in proportion.

Concept Used:

If a, b, c, and d are in proportion,

then, a/b = c/d

Calculation:

When x is added to each number the numbers will be,

(10 + x), (23 + x), (15 + x), and (33 + x)

⇒ (10 + x)/(23 + x) = (15 + x)/(33 + x)

⇒ (10 + x)(33 + x) = (15 + x)(23 + x)

⇒ 330 + 10x + 33x + x² = 345 + 15x + 23x + x²

⇒ 48x – 43x = 345 – 330

⇒ 5x = 15

⇒ x = 15/5

⇒ x = 3

The value of (x + 5)

⇒ 3 + 5

⇒ 8

∴ The value of (x + 5) is 8.