Approximation and Simplification Quiz with Explanation for SBI PO 2021 , NRA CET , IBPS PO , IBPS RRB Scale 1 , RRB Office Assistant , LIC AAO , NIACL

Direction: What approximate value should come in place of question mark.
Important for :
1
(251.87 × 8 × 6.99) ÷ 25 = 11.986 + ?
» Explain it
D
11.986 + ? = (251.87 × 8 × 6.99) ÷ 25

⇒ 12 + ? ≈ (252 × 8 × 7) ÷ 25

⇒ 12 + ? = (10.08 × 8 × 7)

⇒ 12 + ? ≈ 560

? = 560 – 12 = 548

Hence, option D is correct.
2
39.99% of {(256.039 – (62 / 2) × 38.23 = ?
» Explain it
C
39.99% of {(256.039 – (62 / 2) × 38.23 = ?

? = 39.99 % of {( 256.039 – (62 / 2)}  38.23

≈ 40% of {256 – (62/2)} × 38

⇒ ? = (256 – 31) × 38

⇒ ? = 40% of 225 × 38

⇒ ? = 90 × 38 = 3420

Hence, option C is correct.

3
(37.12)2 + (43.88)2 = (?2 – √2600) × √1297
» Explain it
D
(37.12)2 + (43.88)2 = (?2 – √2600) × √1297

⇒ (37)2 + (44)2  ≈ (?2 – √2601) × √1296

?2 – 51 = {(372 + 442) / 36} = {(1369 + 1936) / 36} = (3305 / 36) = 91.8

⇒ ?2 = 91.8 + 51 = 142.80 ≈ 144

⇒ ? = √144 = 12

Hence, option D is correct.

4

» Explain it
B
In Approximation,

7241 × (16 / 6) + 412 ÷ ? = 19377

19309.33 + 412 ÷ ? = 19377

412 ÷ ? = 19377 – 19309 = 68

? = 412 ÷ 68

? = (412 / 68) = 6.05 = ≈ 6

Hence, option B is correct.
5
(?)2 + (125)2 = (250.13)2 – (95.12)2 – 5680
» Explain it
D
(?)2 + (125)2 = (250.13)2 – (95.12)2 – 5680

(?)2 + 15625 = ≈ (250)2 – (95)2 – 5680

(?)2 + 15625 = 62500 – 9025 – 5680

(?)2 + 15625 = 47795

(?)2 = 47795 – 15625 = 32170

? = 179.35

? ≈ 179

Hence, option D is correct.