Find the least number which must be added to 6412 so as to get a perfect square. Also find the square root of the perfect square so obtained.

1. 147; 81
2. 147; 83
3. 149; 81
4. 149; 83

Solution:

Correct Answer: Option (c) 149; 81

Explanation:

From the given options, we can find the solution.

(a) 6412 + 147 = 6559, which is not a pefect square

(b) 6412 + 147 = 6559, which is not a perfect square

(c) 6412 + 149 = 6561, which is a perfect square of 81.

Hence, option (c) is the correct answer.