Approximation Quiz for SBI Clerk Pre, IBPS Clerk Pre, IBPS RRB, 2018

Direction: What approximate value should come in the place of question mark (?) in the following questions?
1
599  ×  401  ÷  31  = ?
51 79 199

» Explain it
B
? =  599  ×  401  ÷  31
51 79 199

? ≈  600  ×  400  ×  200
50 80 30

? ≈ 400

Hence, option B is correct.

2
441.01 – 232.9 + 1649.99 = ? + 1225.92
» Explain it
E
441.01 – 232.9 + 1649.99 = ? + 1225.92

? = 441.01 – 232.9 + 1649.99 – 1225.92

? ≈ 441 – 233 + 1650 – 1226  ≈ 632

Hence, option E is correct.

3
(21.5% of 1001)1/3 + (43% of 599)1/2 = ?
» Explain it
D
? = (21.5% of 1001)1/3 + (43% of 599)1/2

≈ (21.5% of 1000)1/3 + (43% of 600)1/2

≈  ( 21.5  × 1000 ) 1/3  +  ( 43  × 600 ) 1/2
100   100  

≈ (215)1/3 + (258)1/2

≈ 6 + 16  ≈ 22

Hence, option D is correct.

4
(524.21 + 126.108) × 21.09 = ?
» Explain it
B
? = (524.21 + 126.108) × 21.09

≈ (524 + 126) × 21

≈ 650 × 21  ≈ 13650

Hence, option B is correct.

5
6399 × 1 5  + 353 ÷ ? = 10444
8
» Explain it
E
6399 × 1 5  + 353 ÷ ? = 10444
8

In approximation,

6400 ×  13  + 353 ÷ ? = 10444
8

10400 + 353 ÷ ? = 10444

353 ÷ ? = 10444 – 10400 = 44

? = 353 ÷ 44  ≈ 8

Hence, option E is correct.