Practice MCQ Questions and Answer on Decimal Fraction

11.

Solve : $$4\frac{2}{3}$$ + $$3\frac{1}{2}$$ - $$1\frac{2}{3}$$ = ?

• (A) $$2\frac{1}{5}$$
• (B) $$2\frac{5}{3}$$
• (C) $$1\frac{3}{4}$$
• (D) $$1\frac{1}{2}$$

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Answer & Solution Answer: Option E Solution: Given $$4\frac{2}{3}$$ + $$3\frac{1}{2}$$ - $$1\frac{2}{3}$$ = $$\frac{14}{3}$$ + $$\frac{7}{2}$$ - $$\frac{5}{3}$$ By taking L.C.M. of 3, 2 and 3 is 6 = $$\frac{28 + 21 - 10}{6}$$ = $$\frac{39}{6}$$ = $$\frac{13}{2}$$ = $$6\frac{1}{2}$$

12.

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

• (A) 404
• (B) 408
• (C) 410
• (D) 414

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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

13.

The correct expression of $$6.\overline{46}$$ in the fractional form is:

• (A) $$\frac{646}{99}$$
• (B) $$\frac{64640}{1000}$$
• (C) $$\frac{640}{100}$$
• (D) $$\frac{640}{99}$$

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 $$\eqalign{ & 6.\overline {46} \cr & = 6 + 0.\overline {46} \cr & = 6 + \frac{{46}}{{99}} \cr & = \frac{{594 + 46}}{{99}} \cr & = \frac{{640}}{{99}} \cr} $$

14.

The value of $$\frac{3.6\times 0.48\times 2.50}{0.12\times 0.09\times 0.5}$$    is :

• (A) 80
• (B) 800
• (C) 8000
• (D) 80000

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 $$\eqalign{ & = \frac{{3.6 \times 0.48 \times 2.50}}{{0.12 \times 0.09 \times 0.5}} \cr & = \frac{{36 \times 48 \times 250}}{{12 \times 9 \times 5}} \cr & = 800 \cr} $$

15.

Which of the following are in descending order of their values ?

• (A) $$\frac{5}{9},\frac{7}{11},\frac{8}{15},\frac{11}{17}$$
• (B) $$\frac{5}{9},\frac{8}{15},\frac{11}{17},\frac{7}{11}$$
• (C) $$\frac{11}{17},\frac{7}{11},\frac{8}{15},\frac{5}{9}$$
• (D) $$\frac{11}{17},\frac{7}{11},\frac{5}{9},\frac{8}{15}$$

Show Answer

 Converting each of the given fractions in to decimal form, we get $$\frac{5}{9}$$ = 0.55 $$\frac{7}{11}$$ = 0.63 $$\frac{8}{15}$$ = 0.533 $$\frac{11}{17}$$ = 0.647 Clearly, 0.647 > 0.63 > 0.55 > 0.533 So, $$\frac{11}{17}$$ > $$\frac{7}{11}$$ > $$\frac{5}{9}$$ > $$\frac{8}{15}$$

16.

47.7 × 12.4 × 8.6 = ?

• (A) 5086.728
• (B) 5218.668
• (C) 5708.428
• (D) 6180.656

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 477 × 124 × 86 = 5086728 Sum of decimal place = 3 ∴ 47.7 × 12.4 × 8.6 = 5086.728

17.

$$\text{Math input error}$$   = ?

• (A) 0.4
• (B) 1.2
• (C) 1.4
• (D) 4

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

18.

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

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

19.

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

• (A) 1
• (B) 0.1
• (C) 0.01
• (D) 10

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

20.

The value of (1.25)³ - 2.25 (1.25)² + 3.75 (0.75)² - (0.75)³ is :

• (A) 1
• (B) $$\frac{1}{2}$$
• (C) $$\frac{1}{4}$$
• (D) $$\frac{1}{8}$$

Show Answer

 Given expression : (1.25)3 - (0.75)3 - 3 × (1.25)2 × 0.75 + 3 × 1.25 × (0.75)2 = (1.25 - 0.75)3 = (0.5)3 = $${\left( {\frac{1}{2}} \right)^3}$$ = $$\frac{1}{8}$$ [∵ (a - b)3 = a3 - b3 - 3a2 b + 3ab2]