Question

Square root of which of the following numbers will not be a whole number?

• A. 49
• B. 25
• C. 40
• D. 81

Answer 1

The correct option is C 40

$\text{Detailed step-by-step solution:}$
We know that the square root of a perfect square whole number is always a whole number.
Square root of a non perfect square whole number is not a whole number.
Let us check the options one-by-one.
a) 25 is a perfect square, i.e., 5 × 5 = 25.
→Square root of 25 will be a whole number.
a) 81 is a perfect square, i.e., 9 × 9 = 81.
→Square root of 81 will be a whole number.
a) 49 is a perfect square, i.e., 7 × 7 = 49.
→Square root of 49 will be a whole number.
a) 40 is not a perfect square.
→Square root of 40 will not be a whole number.

So, option D is the correct answer.