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

Direction: What approximate value should come in place of question mark.
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 )  × 38.23 =  ?
2
» Explain it
C
39.99% of  ( 256.039 –   62 )  × 38.23 =  ?
2

? = 39.99% of  ( 256.039 –  62 )  × 38.23
2

≈ 40% of  ( 256 –  62 )  × 38
2

⇒ ? = (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  =  1369 + 1936  =  3305  = 91.8
36 36 36

⇒ ?2 = 91.8 + 51 = 142.80 ≈ 144

⇒ ? = √144 = 12

Hence, option D is correct.
4
7241 × 2 4 + 412 ÷ ? = 19377
6
» Explain it
B
In Approximation,

7241 ×  16  + 412 ÷ ? = 19377
6

19309.33 + 412 ÷ ? = 19377

412 ÷ ? = 19377 – 19309 = 68

? = 412 ÷ 68

? =  412  = 6.05 = ≈ 6
68
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.