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

Question: 1

The least perfect square number divisible by 3, 4, 5, 6 and 8 is

(A) 1200

(B) 2400

(C) 3600

(D) 4800

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.

Question: 2

1.52 × \$\$√0.0225\$\$ = ?

(A) 0.3375

(B) 0.0375

(C) 3.275

(D) 32.75

Ans: A

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

= 2.25 × 0.15 = 0.3375.

Question: 3

The number of digits in the square root of 625685746009 is

(A) 3

(B) 4

(C) 5

(D) 6

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.

Question: 4

(\$\$√{225/729}\$\$ - \$\$√{25/144}\$\$) ÷ \$\$√{16/81}\$\$ = ?

(A) \$\${1}/{48}\$\$

(B) \$\${5}/{16}\$\$

(C) \$\${5}/{48}\$\$

(D) \$\${6}/{18}\$\$

Ans: B

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

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

Question: 5

If \$\$√3^n\$\$ = 729, then the value of n is

(A) 6

(B) 8

(C) 10

(D) 12

Ans: D

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

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