Percentage - Aptitude MCQ Questions and Solutions with Explanations

21

Two persons contested an election of Parliament. The winning candidate secured 57% of the total votes polled and won by a majority of 42000 votes. The number of total votes polled is :

A) 500000 B) 600000 C) 300000 D) 400000

Discuss

Answer & Solution

Answer: Option C

Solution:

Let the total number of votes = 100x
Winner candidate get 57% of vote i.e. = 57x and losser will get = 100x - 57x = 43x
According to the question,
57x - 43x = 42000
⇒ 14x = 42000
⇒ x = 3000
Total votes = 100x
= 100 × 3000
= 300000

22

In a factory 60% of the workers are above 30 years and of these 75% are male and the rest are females. If there are 1350 male workers above 30 years, the total number of workers in the factory is :

A) 3000 B) 2000 C) 1800 D) 1500

Discuss

Answer & Solution

Answer: Option A

Solution:

Given,
60% of work whose age is 30 above
1350 males work whose age is 30 above.
75% of workers are male whose age are 30 above.
25% of female workers whose ages are 30 above.
Number of female work whoes age 30 above
= $$\frac{{1350}}{{75}} \times 25 = 450$$
total number of work whoes age are 30 above = 1350 + 450 = 1800(60% of the work)
Total number of work = $$\frac{{1800}}{{60}} \times 100 = 3000$$

23

In the last financial year, a car company sold 41800 cars. In this year, the target is sale 51300 cars. By what percent must the sale be increased ?

A) $$11\frac{9}{22}$$% B) $$8\frac{9}{22}$$% C) $$8\frac{11}{23}$$% D) $$22\frac{8}{11}$$%

Discuss

Answer & Solution

Answer: Option D

Solution:

Percentage increase :
= $$\frac{51300 - 41800}{41800}$$ × 100
= $$\frac{9500}{41800}$$ × 100
= $$\frac{9500}{418}$$
= $$\frac{500}{22}$$
= $$\frac{250}{11}$$
= $$22\frac{8}{11}$$%

24

One third of a number is 96. What will 67% of that number be ?

A) 192.96 B) 181.44 C) 169.92 D) 204.48

Discuss

Answer & Solution

Answer: Option A

Solution:

Let the number = x
⇒ $$\frac{1}{3}$$ × x = 96
⇒ x = 288
⇒ Required answer :
= $$\frac{67}{100}$$ × 288
= 192.96

25

If the duty on an article is reduced by 40% of his present rate by how much percent must its consumption increase in order that the revenue remains unaltered ?

A) 60% B) $$62\frac{1}{3}$$% C) 72% D) $$66\frac{2}{3}$$%

Discuss

Answer & Solution

Answer: Option D

Solution:

% change = $$\frac{{\text{R}}}{{100 \pm {\text{R}}}}$$ × 100%
Required answer :
= $$\frac{40}{100 - 40}$$ × 100
= $$\frac{40}{60}$$ × 100
= $$\frac{200}{3}$$
= $$66\frac{2}{3}$$%

26

If the numerator of a fraction is increased by 20% and the denominator is decreased by 5%, the value of the new fraction becomes $$\frac{5}{2}$$. The original fraction is :

A) $$\frac{24}{19}$$ B) $$\frac{3}{18}$$ C) $$\frac{95}{48}$$ D) $$\frac{48}{95}$$

Discuss

Answer & Solution

Answer: Option C

Solution:

Let the fraction = $$\frac{x}{y}$$
According to the question,
$$\frac{x × 120}{y × 95}$$ = $$\frac{5}{2}$$
$$\frac{x}{y}$$ = $$\frac{5 × 95}{2 × 120}$$
$$\frac{x}{y}$$ = $$\frac{95}{48}$$

27

A line of length 1.5 metres was measured as 1.55 metres by mistakes. What will be the value of error percent ?

A) 0.05% B) $$3\frac{7}{31}$$% C) $$3\frac{1}{3}$$% D) 0.08%

Discuss

Answer & Solution

Answer: Option C

Solution:

Percentage error :
= $$\frac{1.55 - 1.50}{1.50}$$ × 100
= $$\frac{0.05}{1.50}$$ × 100
= $$\frac{5}{150}$$ × 100
= $$\frac{5 × 2}{3}$$
= $$\frac{10}{3}$$
= $$3\frac{1}{3}$$%

28

A reduction of 20% in the price of wheat enables Bhuvnesh to buy 5 kg more wheat for Rs. 320. The original rate (in rupees per kg) of wheat was :

A) 16 B) 18 C) 20 D) 21

Discuss

Answer & Solution

Answer: Option A

Solution:

Let the initial expenditure = 100 units
Percentage mcq solution image

Increase in consumption
= $$\frac{20}{80}$$ = $$\frac{1}{4}$$
1 unit = 5 kg
Original consumption
= 5 × 4 = 20 kg
New consumption
= 5 × 5 = 25 kg
Original price = $$\frac{320}{20}$$ = 16 per kg

29

If the height of a cylinder is increased by 15% and the radius of its base is decreased by 10% then the percentage change in its curved surface area is :

A) 2.5% increased B) 3.5% increased C) 2.5% decreased D) 3.5% decreased

Discuss

Answer & Solution

Answer: Option B

Solution:

Increase in height = 15% = $$\frac{3}{20}$$
Decrease in base radius = 10% = $$\frac{1}{10}$$

	Initial	Final
Radius	10	9
height	20	23
Area	200	207

Increment in Area = 207 - 200 = 7
Required % increase in area
= $$\frac{7}{200}$$ × 100
= 3.5%

30

Two numbers are respectively 20% and 50% of the third number. What percent is the first number of the second ?

A) 10% B) 20% C) 30% D) 40%

Discuss

Answer & Solution

Answer: Option D

Solution:

Let the 3^rd number is 100
According to the question,
$$\eqalign{ & \,{1^{{\text{st}}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{2^{{\text{nd}}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{3^{{\text{rd}}}} \cr & 20\,\,\,\,\,\,\,:\,\,\,\,\,\,\,\,50\,\,\,\,\,\,\,\,:\,\,\,\,\,\,\,100 \cr} $$
Required % = $$\frac{20}{50}$$ × 100 = 40%