Decimal Fraction - Aptitude MCQ Questions and Solutions with Explanations

91

The value of $$\left( {0.\overline 2 + 0.\overline 3 + 0.\overline {32} } \right)$$ is :

A) $$0.\overline {77} $$ B) $$0.\overline {82} $$ C) $$0.\overline {86} $$ D) $$0.\overline {87} $$

Discuss

Answer & Solution

Answer: Option D

Solution:

$$\eqalign{ & = 0.\overline 2 + 0.\overline 3 + 0.\overline {32} \cr & = \left( {\frac{2}{9} + \frac{3}{9} + \frac{{32}}{{99}}} \right) \cr & = \left( {\frac{{22 + 33 + 32}}{{99}}} \right) \cr & = \frac{{87}}{{99}} \cr & = 0.\overline {87} \cr} $$

92

555.05 + 55.5 + 5.55 + 5 + 0.55 = ?

A) 621.65 B) 634.85 C) 647.35 D) 655.75 E) None of these

Discuss

Answer & Solution

Answer: Option A

Solution:

93

$${2.8\overline {768} }$$ is equal to :

A) $$2\frac{878}{999}$$ B) $$2\frac{9}{10}$$ C) $$2\frac{292}{333}$$ D) $$2\frac{4394}{4995}$$

Discuss

Answer & Solution

Answer: Option C

Solution:

$$\eqalign{ & = 2.8\overline {768} \cr & = 2 + 0.8\overline {768} \cr & = 2 + \frac{{8768 - 8}}{{9990}} \cr & = 2 + \frac{{8760}}{{9990}} \cr & = 2\frac{{292}}{{333}} \cr} $$

94

40.04 ÷ 0.4 = ? × 0.05

A) 20.02 B) 20.2 C) 200.2 D) 2002

Discuss

Answer & Solution

Answer: Option D

Solution:

Let 40.04 ÷ 0.4 = x × 0.05
Then, $$\frac{40.04}{0.4}$$ = 0.05x
⇒ $$\frac{400.4}{4}$$ = 0.05x
⇒ 0.05x = 100.1
⇒ x = $$\frac{100.1}{0.05}$$
⇒ x = $$\frac{10010}{5}$$ = 2002

95

Solve : 48.2 × 2.5 × 2.2 + ? = 270

A) 6.5 B) 2.8 C) 4.9 D) 3.4 E) 1.2

Discuss

Answer & Solution

Answer: Option C

Solution:

Let the missing number be x
Given, 48.2 × 2.5 × 2.2 + x = 270
⇒ x = 270 - 48.2 × 2.5 × 2.2
⇒ x = 270 - 265.1
⇒ x = 4.9
Hence, the number is 4.9

96

(78.95)² - (43.35)² = ?

A) 4148 B) 4235.78 C) 4305 D) 4353.88 E) None of these

Discuss

Answer & Solution

Answer: Option D

Solution:

(78.95)² - (43.35)²
= (78.95 + 43.35) (78.95 - 43.35)
= 122.3 × 35.6
= 4353.88
[∵ a² - b² = (a + b) (a - b)]

97

Solve 2.5 × 4.8 + 7.2 × 1.5 - 1.2 × 14 = ?

A) 1.2 B) 6.5 C) 4 D) 4.8 E) 6

Discuss

Answer & Solution

Answer: Option E

Solution:

Let the missing number be x
x = 2.5 × 4.8 + 7.2 × 1.5 - 1.2 × 14
x = (12 + 10.8 - 16.8)
x = 6

98

10.0001 + 9.9999 - 8.9995 = ?

A) 9.0005 B) 10.9995 C) 11.0001 D) 11.0005

Discuss

Answer & Solution

Answer: Option D

Solution:

10.0001 + 9.9999 - 8.9995
= 20.0000 - 8.9995
= 11.0005

99

Solve : $$2\frac{2}{9}$$ + $$4\frac{1}{18}$$ - $$1\frac{1}{2}$$ = ?

A) $$4\frac{5}{9}$$ B) $$4\frac{7}{9}$$ C) $$5\frac{8}{9}$$ D) $$6\frac{1}{2}$$ E) $$5\frac{2}{3}$$

Discuss

Answer & Solution

Answer: Option B

Solution:

$$2\frac{2}{9}$$ + $$4\frac{1}{18}$$ - $$1\frac{1}{2}$$ = ?
Let the missing number be x
x = $$\frac{20}{9}$$ + $$\frac{73}{18}$$ - $$\frac{3}{2}$$
L.C.M. of 9, 18 and 2 is 18
x = $$\frac{40 + 73 - 27}{18}$$
x = $$\frac{86}{18}$$
x = $$\frac{43}{9}$$
x = $$4\frac{7}{9}$$

100

Which of the following is closest to zero ?

A) $${\left( {0.09} \right)^2}$$ B) $$0.09$$ C) $${\left( {1 - 0.9} \right)^2}$$ D) $$1 - {\left( {0.9} \right)^2}$$

Discuss

Answer & Solution

Answer: Option A

Solution:

(a) (0.09)² = 0.0081
(b) 0.09
(c) (1 - 0.9)² = (0.1)² = 0.01
(d) 1 - (0.9)² = 1 - 0.81 = 0.19
Clearly, 0.0081 < 0.01 < 0.09 < 0.19
So, 0.0081 is closest to zero.