Practice MCQ Questions and Answer on Decimal Fraction

81.

The place value of 9 in 0.06945 is :

• (A) $$9$$
• (B) $$\frac{9}{10}$$
• (C) $$\frac{9}{100}$$
• (D) $$\frac{9}{1000}$$

Show Answer

 9 is at thousandths place in 0.06945 So, place value of 9 = $$\frac{9}{1000}$$

82.

Out of the fractions $$\frac{9}{31}$$, $$\frac{3}{17}$$, $$\frac{6}{23}$$, $$\frac{4}{11}$$ and $$\frac{7}{25}$$ which is the largest ?

• (A) $$\frac{9}{31}$$
• (B) $$\frac{3}{17}$$
• (C) $$\frac{6}{23}$$
• (D) $$\frac{4}{11}$$

Show Answer

 Converting each of the given fractions into decimal form, we get: $$\frac{9}{31}$$ = 0.29 $$\frac{3}{17}$$ = 0.176 $$\frac{6}{23}$$ = 0.26 $$\frac{4}{11}$$ = 0.363 $$\frac{7}{25}$$ = 0.28 Clearly, 0.363 > 0.29 > 0.28 > 0.26 > 0.176 So, $$\frac{4}{11}$$ > $$\frac{9}{31}$$ > $$\frac{7}{25}$$ > $$\frac{6}{23}$$ > $$\frac{3}{17}$$

83.

Solve : 48.2 × 2.5 × 2.2 + ? = 270

• (A) 6.5
• (B) 2.8
• (C) 4.9
• (D) 3.4

Show Answer

 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

84.

$$\left(\frac{1.49\times 14.9-0.51\times 5.1}{14.9-5.1}\right)$$     is equal to :

• (A) 0.20
• (B) 2.00
• (C) 20
• (D) 22

Show Answer

 $$\eqalign{ & \left( {\frac{{1.49 \times 1.49 \times 10 - 0.51 \times 0.51 \times 10}}{{1.49 \times 10 - 0.51 \times 10}}} \right) \cr & = \frac{{10\left[ {{{\left( {1.49} \right)}^2} - {{\left( {0.51} \right)}^2}} \right]}}{{10\left( {1.49 - 0.51} \right)}} \cr & = \left( {1.49 + 0.51} \right) \cr & = 2 \cr} $$

85.

$$\text{Math input error}$$   is simplified to :

• (A) 1
• (B) 0.1
• (C) 0.01
• (D) 10

Show Answer

 Given expression : = $$\frac{441 × 16}{21 × 16 × 21}$$ = $$\frac{{7056}}{{7056}}$$ = 1

86.

617 + 6.017 + 0.617 + 6.0017 = ?

• (A) 6.2963
• (B) 62.965
• (C) 629.6357
• (D) None of these

Show Answer

 $$\eqalign{ & 617.00 \cr & \,\,\,\,\,\,\,6.017 \cr & \,\,\,\,\,\,\,0.617 \cr & + \,\,\,6.0017 \cr & - - - - - - \cr & \,\,\,629.6357 \cr & - - - - - - \cr} $$

87.

The expression (11.98 × 11.98 + 11.98 × X + 0.02 × 0.02) will be a perfect square for X equal to:

• (A) 0.02
• (B) 0.2
• (C) 0.04
• (D) 0.4

Show Answer

 Given expression = (11.98)2 + (0.02)2 + 11.98 × X For the given expression to be a perfect square, (a + b)2 = a2 + b2 + 2ab we must have 11.98 × X = 2 × 11.98 × 0.02 ∴ X = 0.04

88.

The value of $$\frac{{\left(2.3\right)}^3-0.027}{{\left(2.3\right)}^2+0.69+0.09}$$    is :

• (A) 0
• (B) 1.6
• (C) 2
• (D) 3.4

Show Answer

 $$\eqalign{ & = \frac{{{{\left( {2.3} \right)}^3} - 0.027}}{{{{\left( {2.3} \right)}^2} + 0.69 + 0.09}} \cr & = \frac{{{{\left( {2.3} \right)}^3} - {{\left( {0.03} \right)}^3}}}{{{{\left( {2.3} \right)}^2} + \left( {2.3 \times 0.3} \right) + {{\left( {0.3} \right)}^2}}} \cr & = \left[ {\frac{{{a^3} - {b^3}}}{{{a^2} + ab + {b^2}}}} \right] \cr & = \left( {a - b} \right) \cr & = \left( {2.3 - 0.3} \right) \cr & = 2 \cr} $$

89.

$$\text{Math input error}$$   = ?

• (A) 0.4
• (B) 1.2
• (C) 1.4
• (D) 4

Show Answer

 Given expression : $$ = \frac{8 - 2.8}{1.3}$$ $$ = \frac{5.2}{1.3}$$ $$ = \frac{52}{13}$$ = 4

90.

The value of $$\text{Math input error}$$     is close to :

• (A) 0.2
• (B) 0.4
• (C) 0.6
• (D) 1

Show Answer

 $$\frac{241.6 × 0.3814 × 6.842}{0.4618 × 38.25 × 73.65}$$ ≈ $$\frac{240 × 0.38 × 6.9}{0.46 × 38 × 75}$$ = $$\frac{240 × 38 × 69}{46 × 38 × 75}$$   × $$\frac{1}{10}$$ = $$\frac{24}{5}$$ × $$\frac{1}{10}$$ = $$\frac{4.8}{10}$$ = 0.48 So, the value is close to 0.4