Approximation and Simplification Questions For SBI Clerk, IBPS Clerk, IBPS RRB, 2018

Directions: What value will come in place of question mark (?) in the following questions: (You are not expected to calculate the exact value)
1
(127.998 × 10.012 × 64001/2) ÷ 100 = (?)2 
» Explain it
C
(?)2 = (127.998 × 10.012 × 64001/2) ÷ 100

≈  (128 × 10 ) × 64001/2  =  128 × 10 × 80
100 100

= 128 × 8 = 1024

∴ ? ≈ 10241/2 = 32

Hence option C is correct
 

2
33% of 810 – 654% of 27 = ?
» Explain it
B
33% of 810 – 654% of 27 = ?
 
26730 ÷ 100 – 17658 ÷ 100 = ?
 
267.3 – 176.58 = ?
 
267 – 177 = ?
 
? = 90

Hence, option B is correct.
 
 
3
11.07 × 81 + 132.04 = ?2
» Explain it
A
11.07 × 81 + 132.04 = ?2
 
11 × 81 + 132 = ?2
 
?2 = 891 + 132
 
?2 = 1023
 
? = 31.98 ≈ 32

Hence, option A is correct.

4
16.97 × 1088.9 + 187 = ?2 + 739
» Explain it
C
16.97 × 1088.9 + 187 = ?2 + 739

17 × 1089 + 187 = ?2 + 739
 
17 × 33 + 187 = ?2 + 739
 
561 + 187 = ?2 + 739
 
748 – 739 = ?2
 
?2 = 9
 
? = 3

Hence, option C is correct.
 
5
[(28 + 48) × (78 + 58)] – (18)2 = ?
» Explain it
A
Follow BODMAS rule to solve this question, as per the order given below,

Step - 1 - 'Brackets' must be solved first, and in the bracket, the BODMAS rule must be followed, 

Step - 2 - Any mathematical 'Of' or 'Exponent' must be solved next,

Step - 3 - Next, the parts of the equation that contain 'Division' and 'Multiplication' are calculated,

Step - 4 - Last but not least, the parts of the equation that contain 'Addition' and 'Subtraction' should be calculated.

[(28 + 48) × (78 + 58)] – (18)2 = ?

⇒ 76 × 136 – 182 = ?

⇒ 10336 – 324 = ?

⇒ ? = 10012

Hence option A is correct.