100+ Surds and Indices Questions for Bank Exams Pdf - 1

Question: 1

49 × 49 × 49 × 49 = 7?

(A) 4

(B) 7

(C) 8

(D) 16

Ans: C

8-25 - 8-26 = $$({1/8^25 – {1/8^26})$$ = $${(8 - 1)}/ {8}^26$$ = 7 × 8-26.

Question: 2

If 2n + 4 - 2n + 2 = 3, then n is equal to

(B) 2

(C) -1

(D) -2

Ans: D

2n + 4 - 2n + 2 = 3

⇔ 2n + 2 (22 - 1) = 3

⇔ 2n + 2 = 1 = 20

⇔ n + 2 = 0

⇔ n = - 2.

Question: 3

21? × 216.5 = 2112.4

(A) 4.4

(B) 5.9

(C) 13.4

(D) 18.9

Ans: B

21? × 216.5 = 2112.4

{∴ am × an = am + n}

⇒ 21? + 6.5 = 2112.4

⇒ ? + 6.5 = 12.4

⇒ ? = 12.4 – 6.5 = 5.9.

Question: 4

$${16 × 32} / {9 × 27 × 81}$$ = ?

(A) $$({2}/{3})^9$$

(B) $$({2}/{3})^11$$

(C) $$({2}/{3})^12$$

(D) $$({2}/{3})^13$$

Ans: A

$${16 × 32} / {9 × 27 × 81}$$

= $${2^4 × 2^5} / {3^2 × 3^3 × 3^4}$$

= $${2}^(4 + 5) / {3}^(2 + 3 + 4)$$

= $${2}^9/{3}^9$$

= $$({2}/{3})^9$$.

Question: 5

$${5.4 ÷ 3 × 16 + 2}/ {18 ÷ 5 × 6 ÷ 3}$$

(A) 2

(B) 3

(C) 4

(D) 5

Ans: A

$${5.4 ÷ 3 × 16 ÷ 2}/ {18 ÷ 5 × 6 ÷ 3}$$

= $${5.4 /3 × 16/2} / {18/5 × 6/3}$$

= $${1.8 × 8} / {3.6 × 2}$$ = 2.

Related Questions