Approximation Test-3 (Approximation of decimal figures)

Answer: Option E

Explanation

Given,

${\left(2.0001\right)}^3\times {\left(1.999\right)}^{-2}÷{\left(3.999\right)}^{-4}$

It can also be approximated

$$\begin{gathered} =\begin{array}{l}{\left(\text{2}\right)}^{\text{3}}\times {\left(\text{2}\right)}^{\text{-2}}÷{\left(\text{4}\right)}^{-4}\end{array} \\ \begin{array}{l}{\text{=(2)}}^{\text{3}}\times \left(2^{-2}\right)÷{\left(4\right)}^{-4}\end{array} \\ \begin{array}{l}{\text{=(2)}}^{\text{3}}\times {\left(2\right)}^{-2+8}\\ \end{array} \\ {\text{=2}}^{\text{3}}\times 2^{8-2}=2^3\times 2^6=2^9=512 \end{gathered}$$

Hence, Option E is correct.

Answer: Option D

Explanation

Given,

55.003×54.998+5.001=?

It can be approximated as

65×55+5=?

= 3025+5

= 3030

Hence, Option D is correct.

Answer: Option A

Explanation

Given,

999.0001 + 899.999- 349.88 =?

It can also be written as

1000+ 900- 350=?

=1900-350

= 1550 ≈ 1549

Hence, Option A is correct.

Answer: Option B

Explanation

Given,

335.01×244.99÷55=?

It can also be written as

335×245÷55=?

[applying the BODMAS]

= 335 ×4.5

= 340 ×4.5

=1530 ≈1550

Hence, option B is correct.

Answer: Option C

Explanation

Given,

67.99% of 1401-13.99% of 1299 =?

It can be approximated as

68% of 1400-14% of 1300 =?

$?=\frac{68}{100}\times 1400-\frac{14}{100}\times 1300$

= 952-182

=770

Hence, Option C is correct.