The square of an odd number cannot have 4 as the unit digit. The square of a 3 digit number will have at least 5 digit and at the most 6 digits.

Correct Option: A

The square of an odd number cannot have 4 as the unit digit. The square of a 3 digit number will have at least 5 digit and at the most 6 digits. So. answer (A) is correct.

74088 = 2 x 2 x 2 x 3 x 3 x 3 x 7 x 7 x 7

Correct Option: A

74088 = 2 x 2 x 2 x 3 x 3 x 3 x 7 x 7 x 7
= (2x2) x (3x3) x (7x7) x (2x3x7)
Least number which should be multiplied to 74088 to make it a Perfect square = 2 x 3 x 7 = 42

Let given expression = x
Then, √12 + x = x

Correct Option: B

Let given expression = x
Then, √12 + x = x
⇒ 12 + x = x²
⇒ x² - x - 12 = 0
⇒ (x - 4) (x + 3) = 0
So, x = 4 (neglecting x = -3)

√1 + 27/169 = (1 + N/13)
∴ √196/169 = (1 + N/13)

Correct Option: A

√1 + 27/169 = (1 + N/13)
∴ √196/169 = (1 + N/13)
⇒ 14/13 = (1 + N/13)
⇒ N/13 = (14/13 - 1 ) = 1/13
∴ N = 1

Given expression = √(121 x 9) / (11 x 11)
= √9

Correct Option: B

Given expression = √(121 x 9) / (11 x 11)
= √9
= 3