Question

If the 2nd term of a GM series is 25, the first and 3rd terms will be _____.

• A. 5,125
• B. 105,5
• C. 5,105
• D. 25,125

Answer 1

The correct option is A 5,125

Geometric mean between two numbers is the mean proportion of the series.

Therefore, let the two numbers be a and b

a/25 = 25/b

=>ab= 25 x 25

Also , a/b = 1/25

b = 25a

so, a (25a) = 25 x 25

=>a² = 25

=> a = 5

Now, b = 25(5)

b = 125

Therefore, the first and the 3rd terms are 5 and 125 respectively.