Decimal Fraction - Aptitude MCQ Questions and Solutions with Explanations

71

11.71 - 0.86 + 1.78 - 9.20 = ?

A) 2.43 B) 3.13 C) 3.43 D) 4.13 E) None of these

Discuss

Answer & Solution

Answer: Option C

Solution:

Given expression :
= (11.71 + 1.78) - (0.86 + 9.20)
= 13.49 - 10.06
= 3.43

72

The product of 0.09 and 0.007 is :

A) 0.6300 B) 0.00063 C) 0.00630 D) 0.000063

Discuss

Answer & Solution

Answer: Option B

Solution:

9 × 7 = 63
Sum of decimal places = 5
∴ 0.09 × 0.007 = 0.00063

73

29.92 × 2.4 + 21.28 × 4.5 = ?

A) 167.568 B) 167.658 C) 176.568 D) 176.658 E) None of these

Discuss

Answer & Solution

Answer: Option A

Solution:

Given expression :
71.808 + 95.76
= 167.568

74

$$1.\overline {27} $$ in the from $$\frac{p}{q}$$ is equal to :

A) $$\frac{127}{100}$$ B) $$\frac{14}{11}$$ C) $$\frac{73}{100}$$ D) $$\frac{11}{14}$$

Discuss

Answer & Solution

Answer: Option B

Solution:

$$\eqalign{ & = 1.\overline {27} \cr & = 1 + 0.\overline {27} \cr & = 1 + \frac{{27}}{{99}} \cr & = 1 + \frac{3}{{11}} \cr & = \frac{{11 + 3}}{{11}} \cr & = \frac{{14}}{{11}} \cr} $$

75

$$\frac{{5.3472 \times 324.23}}{{3.489 \times 5.42}}$$ is the same as :

A) $$\frac{{53472 \times 3.2423}}{{3.489 \times 54.2}}$$ B) $$\frac{{53472 \times 32423}}{{3489 \times 542}}$$ C) $$\frac{{534.72 \times 324.23}}{{34.89 \times 5.42}}$$ D) $$\frac{{53472 \times 3242.3}}{{3489 \times 542}}$$

Discuss

Answer & Solution

Answer: Option D

Solution:

For the expressions to be equivalent, the difference between the sum of the decimal places in the numerator and that in the denominator must be equal.
This difference is 1 in the given expression and 1 in (D).
So, (D) is the answer.

76

$$0.4\overline {23} $$ is equivalent to the fraction :

A) $$\frac{94}{99}$$ B) $$\frac{49}{99}$$ C) $$\frac{491}{990}$$ D) $$\frac{419}{990}$$

Discuss

Answer & Solution

Answer: Option D

Solution:

$$\eqalign{ & = 0.4\overline {23} \cr & = \frac{{423 - 4}}{{990}} \cr & = \frac{{419}}{{990}} \cr} $$

77

4.4 × 5.8 × 11.5 - 141.27 = ?

A) 121.17 B) 147.51 C) 152.21 D) 187.95 E) None of these

Discuss

Answer & Solution

Answer: Option C

Solution:

Given expression :
= 293.48 - 141.27
= 152.21

78

Simplify : $$\frac{{5.32 \times 56 + 5.32 \times 44}}{{{{\left( {7.66} \right)}^2} - {{\left( {2.34} \right)}^2}}}$$

A) 7.2 B) 8.5 C) 10 D) 12

Discuss

Answer & Solution

Answer: Option C

Solution:

Given expression :
$$\eqalign{ & = \frac{{5.32 \times \left( {56 + 44} \right)}}{{\left( {7.66 + 2.34} \right)\left( {7.66 - 2.34} \right)}} \cr & = \frac{{5.32 \times 100}}{{10 \times 5.32}} \cr & = 10 \cr} $$

79

Express $$0.29\overline {56} $$ in the form $$\frac{{\text{p}}}{{\text{q}}}$$ (vulgar fraction)

A) $$\frac{2956}{1000}$$ B) $$\frac{2956}{10000}$$ C) $$\frac{2927}{9900}$$ D) None of these

Discuss

Answer & Solution

Answer: Option C

Solution:

$$\eqalign{ & = 0.29\overline {56} \cr & = \frac{{2956 - 29}}{{9900}} \cr & = \frac{{2927}}{{9900}} \cr} $$

80

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

A) 1680 B) 1940 C) 1640 D) 1880 E) 1780

Discuss

Answer & Solution

Answer: Option D

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