100+ Square Root and Cube Root Questions for Bank Exams - 1

Ans: C

L.C.M. of 3, 4, 5, 6, 8 is 120. Now, 120 = 2 × 2 × 2 × 3 × 5.

To make it a perfect square, it must be multiplied by 2 × 3 × 5.

So, required number = 2² × 2² × 3² × 5² = 3600.

Ans: A

1.5² × $$√0.0225$$ = 1.5² × $$√{225/10000}$$ = $$2.25 × {15}/{100}$$

= 2.25 × 0.15 = 0.3375.

Ans: D

The number of digits in the square root of a perfect square number of n digits is

i. $${n}/{2}$$, if n is even

ii. $${n+1} / {2}$$, if n is odd

iii. Here, n = 12. So required number of digits = $${n}/{2}$$ = $${12}/{2}$$ = 6.

Ans: B

Given expression = ($$√225 / √729$$ - $$√25/√144$$) ÷ $$√16 / √81$$

= $$({15}/{27} – {5}/{12})$$ ÷ $${4}/{9}$$ = $$({15}/{108} × {9}/{4})$$ = $${5}/{16}$$.

Ans: D

$$√3^n$$ = 729 = 3⁶ ⇔ ($$√3^n$$)² = (3⁶)² ⇔ $$3^n$$ = 3¹² ⇔ n = 12.