Directions: Find the approximate value which should come in place of Question mark (?) in the following question.
1
27.003 × 4.99 × (145.003 ÷ 28.97) – (12.001 × 3.94) + 127.03 – 29.14 = ?
» Explain it
B
? ≈ 27 × 5 ×  145  – 12 × 4 + 127 – 29
29
≈ 135 × 5 – 48 + 127 – 29

= 675 – 48 + 127 – 29

= 802 – 77 = 725

Hence, option B is correct.
 
2
20.01 × 1024 + 159 = ?2 + 536
» Explain it
B
20.01 × 1024 + 159 = ?2 + 536

20 × 1024 + 159 = ?2 + 536

20 × 32 + 159 = ?2 + 536

640 + 159 = ?2 + 536

799 – 536 = ?2

?2 = 263

? = 16.21 ≈ 16

Hence, option B is correct.

3
25.1% of 5902 = ? × 55.96 ÷ 3.82 × 20
» Explain it
D
25.1 % of 5902 = ? × 55.96 ÷ 3.82 ×20

= 5902 ×  1  = ? × 56 ÷ 4 × 20
4

1476 ÷ 14 ÷ 20 = ?

? = 5.27 ≈ 5

Hence, option D is correct.

4
53.15% of 426 – 30.45% of 745 = ?2 – 512 – 1600
» Explain it
C
53.15% of 426 – 30.45% of 745 = ?2 – 512 – 1600

53% of 426 – 30% of 745 = ?2 – 512 – 40

225.78 – 223.5 + 512 + 40 = ?2

?2 = 226 – 223 + 512 + 40

?2 = 555

?2 = 23.55 ≈ 24

Hence. option C is correct.

5
27.031 × 328.001 + 37.081 – ? = 2628.31 + 37.035 – 36.745 × 4.125
» Explain it
C
27 × 328 + 37 – ? ≈ 2628 + 37 – 37 × 4
 
Or, ? ≈ (27 × 328 + 37) – (2628 + 37 – 37 × 4) = ( 8856 + 37) – (2665 – 148)
 
= 8893 – 2517 = 6376
 
Hence, option C is correct.