Question

The 1^st, 2^nd and 4^th terms of a proportion are 12, 21 and 14 respectively. Find the 3^rd term.
1. 3
2. 6
3. 5
4. 8

Answer 1

Correct Answer - Option 4 : 8

Formula Used:

If numbers are in proportion

Product of the first term and 4^th term = Product of the second term and 3^rd term

Calculation:

Let th third number be x

12 ∶ 21 ∶∶ x ∶ 14

Product of the first term and 4^th term = Product of the second term and 3^rd term

⇒ 12 × 14 = 21 × x

⇒ x = 8 

∴ The value of x is 8

The correct option is 4 i.e. 8