Exercise : 2


1. What should come in the place of question mark (?) in the following equation?

8265 + 2736 + 41320 = ?

(a) 51321
(b) 52231
(c) 52321
(d) 52311
(e) None of these
2. What should come in place of the question mark (?) in the following equation?

\(\frac{\left ( 7 \times ? \right )^{2}}{49} = \sqrt{81}\)
(a) 9
(b) 2
(c) 3
(d) 4
(e) None of these
3. What approximate value will come in place of the question mark (?) in the following equation?

\(\sqrt{625.04} \times 16.96 + 136.001 \div 17 = ?\)
(a) 418
(b) 441
(c) 425
(d) 433
(e) 449
Ans.d

\(? = \sqrt{625.04} \times 16.96 + 136.001 \div 17\) ≈ 25 × 17 + 8

= 425 + 8 = 433

4. What approximate value should come in place of the question mark?

48.25 × 150 + 32 × 16.5 – 125 × 10.5 = ?

(a) 6200
(b) 7500
(c) 6450
(d) 7100
(e) 6700
5. What approximate value should come in place of the question mark (?).

36.0001 ÷ 5.9998 × √? = 108.0005

(a) 325
(b) 316
(c) 256
(d) 16
(e) 18
Ans.e

Using approximation, we get 366 × √? = 108

or, √? = 1086

or, √? = 18

or, ? = 324 ≈ 325

6. What should come in place of question mark (?)?

138.009 + 341.981 – 146.305 = 123.6 + ?

(a) 210.85
(b) 120.85
(c) 220.085
(d) 120.085
(e) None of these
Ans.e

? = 138.009 + 341.981 – 146.305 – 123.60

∴ ? = 210.085

7. What should come in place of question mark (?) in the following equation ?

197 × ? + 162 = 2620

(a) 22
(b) 12
(c) 14
(d) 16
(e) None of these
Ans.b

? = \(\frac{2620 - 256}{197} = 12\)

8. What approximate value should come in place of question mark (?) in the following equation

287.532 + 1894.029 – 657.48 = 743.095 + ?

(a) 870
(b) 790
(c) 780
(d) 770
(e) 890
Ans.c

? = 285 + 1895 – 655 – 745 or, ? = 780

9. What should come in place of question mark (?) in the following equation ?

27311 + 11825 - 32522 = 11611 + ?

(a) 113910
(b) 111911
(c) 90910
(d) 101911
(e) None of these
Ans.e

? = (27 + 118 – 32 – 11) + (311 + 25 - 522 - 611)

or, ? = 102 + \(\left (\frac{30 + 44 - 25 - 60}{110} \right ) = 12\)

or,? = 102 – 110 = 101910

10. What should come in the place of the question mark(?) in the following equation?

2125 ÷ 920 × 512 ÷ 1017

(a) 777125
(b) 11910
(c) 119450
(d) 12990
(e) None of these
Ans.d

? = 2125 × 209 × 512 ÷ 1710 = 11990 = 12990