Percentage - Aptitude MCQ Questions and Solutions with Explanations

31

Find the : (550% of 250) ÷ 275 = ?

A) 15 B) 0.5 C) 1.5 D) 25 E) None of these

Discuss

Answer & Solution

Answer: Option E

Solution:

= (550% of 250) ÷ 275
= $$\frac{550}{100}$$ × 250 × $$\frac{1}{275}$$
= $$\frac{55 × 25}{275}$$
= 5

32

By how much percent is four-fifths of 70 lesser than five-sevenths of 112 ?

A) 24% B) 30% C) 36% D) 42%

Discuss

Answer & Solution

Answer: Option B

Solution:

$$\frac{4}{5}$$ × 70 = 56 and $$\frac{5}{7}$$ × 112 = 80
∴ Required percentage :
$$\eqalign{ & = \left( {\frac{{80 - 56}}{{80}} \times 100} \right)\% \cr & = \left( {\frac{{24}}{{80}} \times 100} \right)\% \cr & = 30\% \cr} $$

33

The firm uses the following function to calculate the production out (PO) : PO = 5.3C² L¹⁵, where C = capital invested and L = labour employed. If the capital invested (C) increases by 20 percent, the change in PO will be :

A) 20% decrease B) 32% increase C) 44% increase D) 56% increase

Discuss

Answer & Solution

Answer: Option C

Solution:

PO_initial = 5.3C² L¹⁵
PO_new = 5.3 (1.2C)² L¹⁵
= 1.44 (5.3C² L¹⁵)
= 1.44PO_initial
Increase in PO = 0.44PO_initial
∴ Increase % = (0.44 × 100)% = 44%

34

On a test consisting of 250 questions, Jassi answered 40% of the first 125 questions correctly. What percent of the other 125 questions does she need to answer correctly for her grade on the entire exam to be 60% ?

A) 60% B) 75% C) 80% D) Cannot be determined E) None of these

Discuss

Answer & Solution

Answer: Option C

Solution:

Number of questions answered correctly = 40% of 125 = 50
For 60% grade, number of questions to be answered correctly = 60% of 250 = 150
Remaining number of questions to be answered correctly
= 150 - 50
= 100
∴ Required percentage
$$\eqalign{ & = \left( {\frac{{100}}{{125}} \times 100} \right)\% \cr & = 80\% \cr} $$

35

Find the 92.5% of 550 = ?

A) 506.45 B) 508.75 C) 518.55 D) 521.65 E) None of these

Discuss

Answer & Solution

Answer: Option B

Solution:

= 92.5% of 550
= $$\frac{925}{10}$$ × $$\frac{1}{100}$$ × 550
= 508.75

36

40% of 265 + 35% of 180 = 50% of ?

A) 84.5 B) 169 C) 253.5 D) 338 E) None of these

Discuss

Answer & Solution

Answer: Option D

Solution:

Let 40% of 265 + 35% of 180 = 50% of x
Then, $$\left( {\frac{40}{{100}} \times 265} \right)$$ + $$\left( {\frac{35}{{100}} \times 180} \right)$$ = $$\left( {\frac{50}{{100}} \times x} \right)$$
⇒ 106 + 63 = $$\frac{x}{2}$$
⇒ x = 169 × 2
⇒ x = 338

37

If a exceeds b by x%, then which one of the following equations is correct ?

A) $$a - b = \frac{x}{100}$$ B) $$b = a + 100x$$ C) $$a = \frac{bx}{100 + x}$$ D) $$a = b + \frac{bx}{100}$$

Discuss

Answer & Solution

Answer: Option D

Solution:

A exceeds b by x%
⇒ a = b + x% of b
⇒ a = b +$$\frac{bx}{100}$$

38

10% of 5 and 5% of 10 add up to

A) 0.10 B) 0.25 C) 1.0 D) 2.5

Discuss

Answer & Solution

Answer: Option C

Solution:

= 10% of 5 + 5% of 10
= $$\left( {\frac{{10}}{{100}} \times 5} \right)$$ + $$\left( {\frac{{5}}{{100}} \times 10} \right)$$
= 0.5 + 0.5
= 1.0

39

In an examination, 30% and 35% students respectively failed in History and Geography while 27% students failed in both subjects. If the number of students passing the examination is 248, find the total number of students who appeared in the examination.

A) 380 B) 400 C) 425 D) 725

Discuss

Answer & Solution

Answer: Option B

Solution:

Percentage of failed candidates = (30 + 35 - 27)% = 38%
Percentage of passed candidates = (100 - 38)% = 62%
Let the total number of students appeared be x
Then, 62% of x = 248
⇒ x = $$\frac{248 × 100}{62}$$
⇒ x = 400

40

In an examination, the percentage of students qualified to the number of students appeared from school A is 70%. In school B, the number of students appeared is 20% more than the students appeared from school A and the number of students qualified from school B is 50% more than the students qualified from school A. What is the percentage of students qualified to the number of students appeared from school B ?

A) 30% B) 70% C) 78.5% D) 87.5%

Discuss

Answer & Solution

Answer: Option D

Solution:

Let number of students appeared from school A = 100
Then, number of students qualified from school A = 70
Number of students appeared from school B = 120
Number of students qualified from school B :
= $$\frac{150}{100}$$ × 70
= 105
∴ Required percentage :
$$\eqalign{ & = \left( {\frac{{105}}{{120}} \times 100} \right)\% \cr & = 87.5\% \cr} $$