Decimal Fraction - Aptitude MCQ Questions and Solutions with Explanations

81

Solve 1599 ÷ 39.99 + $$\frac{4}{5}$$ × 2449 - 120.05 = ?

A) 1880 B) 1940 C) 1680 D) 1980

Discuss

Answer & Solution

Answer: Option A

Solution:

Given = 1599 ÷ 39.99 + $$\frac{4}{5}$$ × 2449 - 120.05
= 1600 ÷ 40 + $$\frac{4}{5}$$ × 2450 - 120
= 1600 ÷ 40 + 1960 - 120
= 40 + 1960 - 120
= 1880

82

If $$\frac{144}{0.144}$$ = $$\frac{14.4}{x},$$ then the value of $$x$$ is :

A) 0.0144 B) 1.44 C) 14.4 D) 144

Discuss

Answer & Solution

Answer: Option A

Solution:

$$\frac{144}{0.144}$$ = $$\frac{14.4}{x}$$
⇒ $$\frac{144 × 1000}{144}$$ = $$\frac{14.4}{x}$$
⇒ x = $$\frac{14.4}{1000}$$
⇒ x = 0.0144

83

999.99 + 99.99 + 9.99 = ?

A) 1019.89 B) 1099.88 C) 1108.99 D) 1109.99 E) None of these

Discuss

Answer & Solution

Answer: Option E

Solution:

84

Which of the following fractions is the largest ?
$$\frac{3}{2}$$, $$\frac{7}{3}$$, $$\frac{5}{4}$$, $$\frac{7}{2}$$

A) $$\frac{7}{3}$$ B) $$\frac{5}{4}$$ C) $$\frac{7}{2}$$ D) $$\frac{3}{2}$$

Discuss

Answer & Solution

Answer: Option C

Solution:

Each fraction is equivalent to decimal
$$\frac{3}{2}$$ = 1.5
$$\frac{7}{3}$$ = 2.3
$$\frac{5}{4}$$ = 1.25
$$\frac{7}{2}$$ = 3.5
Hence, $$\frac{7}{2}$$ is largest fraction.

85

$$\left( {8.3\overline 1 + 0.\overline 6 + 0.00\overline 2 } \right)$$ is equal to :

A) $${8.9\overline {12} }$$ B) $${8.\overline {912} }$$ C) $${8.9\overline {79} }$$ D) $${8.97\overline {9} }$$

Discuss

Answer & Solution

Answer: Option D

Solution:

$$\eqalign{ & \left( {8.3\bar 1 + 0.\bar 6 + 0.00\bar 2} \right) \cr & = 8 + \frac{{31 - 3}}{{90}} + \frac{6}{9} + \frac{2}{{900}} \cr & = \frac{{7200 + 280 + 600 + 2}}{{900}} \cr & = \frac{{8082}}{{900}} \cr & = 8\frac{{882}}{{900}} \cr & = 8 + \frac{{979 - 97}}{{900}} \cr & = 8.97\bar 9 \cr} $$

86

Solve $$\frac{?}{529}$$ = $$\frac{329}{?}$$

A) 404 B) 408 C) 410 D) 414 E) 416

Discuss

Answer & Solution

Answer: Option E

Solution:

Let the missing number be x,
$$\frac{x}{529}$$ = $$\frac{329}{x}$$
x × x = 529 × 329
x = $$\sqrt {174041} $$
x = 417.18 $$ \approx $$ 416
Hence, the number is 416

87

$$\left( {0.34\overline {67} + 0.13\overline {33} } \right)$$ is equal to :

A) $${0.4\overline 8 }$$ B) $${0.\overline 48 }$$ C) $${0.48\overline {01} }$$ D) $${0.48}$$

Discuss

Answer & Solution

Answer: Option C

Solution:

$${0.34\overline {67} + 0.13\overline {33} }$$
= $$\frac{3467 - 34}{9900}$$ + $$\frac{1333 - 13}{9900}$$
= $$\frac{3433 + 1320}{9900}$$
= $$\frac{4753}{9900}$$
= $$\frac{4801 - 48}{9900}$$
= $${0.48\overline {01} }$$

88

Solve $$\sqrt {197} $$ × 6.99 + 626.96 = ?

A) 885 B) 725 C) 825 D) 650 E) 675

Discuss

Answer & Solution

Answer: Option B

Solution:

Given $$\sqrt {197} $$ × 6.99 + 626.96
≈ $$\sqrt {196} $$ × 7 + 627
= 14 × 7 + 627
= 98 + 627
= 725

89

636.66 + 366.36 + 363.33 = ?

A) 1336.35 B) 1363.25 C) 1366.25 D) 1636.25 E) None of these

Discuss

Answer & Solution

Answer: Option E

Solution:

90

Solve : $$\frac{{{{\left( {36.54} \right)}^2} - {{\left( {3.46} \right)}^2}}}{?} = 40$$

A) 3.308 B) 4 C) 33.08 D) 330.8

Discuss

Answer & Solution

Answer: Option C

Solution:

Let, the missing number be x,
Then,
$$\frac{{{{\left( {36.54} \right)}^2} - {{\left( {3.46} \right)}^2}}}{x} = 40$$
x = $$\frac{{{{\left( {36.54} \right)}^2} - {{\left( {3.46} \right)}^2}}}{40} $$
x = $$\frac{{{{\left( {36.54} \right)}^2} - {{\left( {3.46} \right)}^2}}}{{36.54 + 3.46}}$$
Let 36.54 = $$a$$ and 3.46 = $$b$$
x = $$\frac{{{a^2} - {b^2}}}{{a + b}}$$
x = (a - b)
x = (36.54 - 3.46)
x = 33.08