Approximation Test-3 (Approximation of decimal figures)

Answer: Option D

Explanation

Given,

(19.97% of 781)+?+(30% of 87)=252

It can be approximated as

(20% of 780)+?+(30% of 87)=252

= 156+?+26≈252

= 182+?≈252

= ? =252-182

= ? =70

Hence, Option D is correct.

Answer: Option E

Explanation

Given,

82.11-21×2.99+?=240

= 82-21×3+?≈ 240

= 82-63+? ≈ 240

= 19+?=240

= ? ≈240-19

= 221

Hence, option E is correct.

Answer: Option C

Explanation

Given,

399.15-12×13.95+?= (24.02)²

It can be approximated as

400-12×14+?= 576

= 400-168+? =576

= 576-400+168

= 344 ≈ 345

Hence, Option C is correct.

Answer: Option D

Explanation

Given,

899.99÷45.012=?-224.488

It can be approximated as

900÷45=?-225

= 20=?-225

= 225+20

= 245

Hence, Option D is correct.

Answer: Option D

Explanation

Given,

$\frac{3}{5} \text{of\hspace{0.17em}}\frac{7}{19}\text{\hspace{0.17em}of\hspace{0.17em}}\frac{15}{28}\mathrm{of} 543=?$

It can be approximated as

$\frac{3}{5} \text{of\hspace{0.17em}}\frac{7}{20}\text{\hspace{0.17em}of\hspace{0.17em}}\frac{15}{30}\mathrm{of} 550=?$

$$\begin{gathered} \begin{array}{l}=\frac{21}{100}\times \frac{1}{2}\times 550=?\text{\hspace{0.17em}\hspace{0.17em}or\hspace{0.17em}}\frac{20}{100}\times \frac{550}{2}=?\\ \end{array} \\ \text{ ?= }\frac{{\displaystyle 550}}{{\displaystyle 5\times 2}} \end{gathered}$$ 

= 55 ≈ 50

Hence, Option D is correct.