Exercise : 6


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

477.5 ÷ 4732 × 47-3 = (√47)?

(a) 3
(b) 212
(c) 6
(d) 3.5
(e) None of these
Ans.c

(47)3 = [(47)1/2]6

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

3313% of 768.9 + 25% of 161.2 – 68.12 = ?

(a) 230
(b) 225
(c) 235
(d) 220
(e) 240
Ans.a

? = 3313% of 768.9 + 25% of 161.2 – 68.12

= 13 of 768.9 + 14 of 161.2 – 68.12

= 256.3 + 40.3 – 68.12 ≈ 230

3. Four of the following five parts (a), (b), (c), (d) and (e) are exactly equal. The number of the part which is not equal to the other four parts is your answer.
(a) 30 × 14 ÷ 7 × 5

(b) 103 – 100 × 7

(c) 5\(\sqrt{3600}\)

(d) 450 ÷ 50 × 50 – 5 × 30

(e) 10 × 3 + 120 × 2

Ans.e

Other parts are equal to 300.

4. Four of the five parts numbered a, b, c, d and e in the following equation are exactly equal. Which of the parts is not equal to the other four? The number of that part is your answer.
(a) 10.36 + 69.802 + 24.938
(b) 2207.1 ÷ 21
(c) 1623% of 630.6
(d) 32.84375 × 3.2
(e) 15 of 19 of 4729.4
Ans.e

The other parts are equal to 105.10.

5. Four of the following five parts numbered (a), (b), (c), (d) and (e) are exactly equal. The number of the part which is not equal to the other four parts is your answer.
(a) 2x2 – 3xy + y2
(b) (2x + y)(x – y)
(c) (x – y)2 + x(x – y)
(d) (2x – y)2 – x(2x – y)
(e) (2x – y)2 – 2x2 + xy
Ans.b

Other parts are equal to

2x2 + y2 – 3xy.

6. Four of the following five parts numbered (a), (b), (c), (d) and (e) are exactly equal. The number of the part which is not equal to the other four parts is your answer.
(a) 75 × 8 ÷ 6
(b) 98 ÷ 2.5 + 15.2 × 4
(c) \(\sqrt{225}\) – 5 × 22
(d) 76 × 1.5 – 5.5 × 2.6
(e) 48 × 1.2 + 127.2 ÷ 3
Ans.d

Check all options one by one.

(a) \(\frac{75 \times 8}{6} = 100\)

(b) 982.5 + (15.2 × 4) = 100

(c) (15 × 8) – (5 × 4) = 100

(d) (76 × 1.5) – (5.5 × 2.6) = 99.7

(e) (48 × 1.2) + 127.23 = 100

7. Four of the following five numbered parts (a), (b), (c), (d) and (e) are equal. The number of the part which is not equal to the other four parts is the answer.
(a) 115 × 8 ÷ 10 + 8
(b) 425 ÷ 17 × 4
(c) 36 × 5 ÷ 6 + 17 × 4
(d) 26 + \(\sqrt{256}\) + 20
(e) 35 × 12 ÷ 14 + 14 × 5
Ans.c

All others are equal to 100. But option (c) gives a value equal to 98.

8. Four of the five parts numbered (a),(b),(c),(d) and (e) in the following equation are exactly equal. Which of the parts is not equal to the other four? The number of that part is the answer.
(a) 45 × 120 + 52 × 10
(b) 113 × 25 × 2
(c) 27 × 25 × 8 + 15 × 6 + 4 × 40
(d) 226 × 5 + 113 × 45 =
(e) 502 × 2 + 13 × 50
Ans.d

Others equal 5650.

9. Four of the following five parts numbered (a), (b), (c), (d) and (e) are exactly equal. The number of the part which is not equal to the other four parts is your answer.
(a) 85 ÷ 17 × 110
(b) 45 × 6 + 75 × 4
(c) 175 ÷ 25 × 75 + 52
(d) 36 × 4 + 212 – 7 × 5
(e) 65 × 12 – 46 × 5
Ans.b

Except it, others are equal to 550.

10. Four of the five parts numbered (a),(b),(c),(d) and (e) in the following sequence are exactly equal. Which part is not equal to the other four? The number of that part is the answer.
(a) 120 × 12 – 22 × 20
(b) 10% of 5000 + 25 of 1200
(c) 80 × 40 – 20 × 110
(d) 8640 ÷ 60 + 53.5 × 16
(e) 5314 – 3029 – 1285
Ans.b

The other parts are equal to 1000.