Exercise : 3


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

69012 – 20167 + (51246 ÷ 6) = ?

(a) 57385
(b) 57286
(c) 57476
(d) 57368
(e) None of these
Ans.e

? = 48845 + 512466 = 48845 + 8541 = 57386

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

98.98 ÷ 11.03 + 7.014 × 15.99 = (?)2

(a) 131
(b) 144
(c) 12
(d) 121
(e) 11
Ans.e

98.98 ÷ 11.03 + 7.014 × 15.99 = (?)2

Suppose ? = x

Then 99 ÷ 11 + 7 × 16 + ≈ 121

(taking approximate value)

∴ x = 11

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

39.05 × 14.95 – 27.99 × 10.12 = (36 + ?) × 5

(a) 22
(b) 29
(c) 34
(d) 32
(e) 25
Ans.e

Solve using approximation

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

2070.50 ÷ 15.004 + 39.001 × (4.999)2 = ?

(a) 1005
(b) 997
(c) 1049
(d) 1213
(e) 1113
Ans.e

2070.50 ÷ 15.004 + 39.001 × (4.999)2 = ?

or? ≈ 2070 ÷ 15 + 39 × 5 × 5

= 138 + 975 = 1113

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

\(\frac{45^{2} \times 27^{2}}{135^{2}} = ?\)
(a) 81
(b) 1
(c) 243
(d) 9
(e) None of these
Ans.a

? = \(\frac{45 \times 45 \times 27 \times 27}{135 \times 135} = 81\)

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

412 × 413 - 813 ÷ 523 = ?

(a) 8
(b) 18134
(c) 13334
(d) 717
(e) None of these
Ans.b

? = 92 × 133 - 253 × 317

= 392 - 2517 = \(\frac{663 - 50}{34} = \frac{613}{34} = 18\tfrac{1}{34}\)

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

85.147 + 34.912 × 6.2 + ? = 802.293

(a) 400
(b) 450
(c) 550
(d) 600
(e) 500
Ans.e

85.147 + 34.912 × 6.2 + ? = 802.293

or, ? = 802.293 – 85.147 – 34.912 × 6.2

≈ 800 – 85 – 35 × 6 ≈ 500

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

9548 + 7314 = 8362 + ?

(a) 8230
(b) 8500
(c) 8410
(d) 8600
(e) None of these
Ans.b

9548 + 7314 = 8362 + ?

or,? = 9548 + 7314 – 8362 = 8500

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

248.251 ÷ 12.62 × 20.52 = ?

(a) 400
(b) 450
(c) 600
(d) 350
(e) 375
Ans.a

248.251 ÷ 12.62 × 20.52 = ?

or,? ≈ 240 ÷ 12 × 20 = 20 × 20 = 400

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

6.595 × 1084 + 2568.34 – 1708.34 = ?

(a) 6,000
(b) 12,000
(c) 10,000
(d) 8,000
(e) 9,000
Ans.d

? ≈ 6.6 × 1080 + 2560 – 1700 ≈ 7128 + 860 ≈ 8000