# Percentage Aptitude Questions and Answers – Quantitative Aptitude

Percentage Aptitude Question and Answer – Formulas & Tricks

Points to Remember:

• Y% is expressed as (Y/100)
• To find percent of (x/y) = ((x/y) * 100)%

Percentage Increase / Decrease:

If the price of a commodity increases by R%, then the reduction in consumption so as not to increase the expenditure is If the price of a commodity decreases by R%, then the increase in consumption so as not to decrease the expenditure is: Population Result:

Let the population of a town be P now and suppose it increases at the rate of R% per annum, then:

• Population after n years = • Population n years ago = Depreciation Results:

Let the present value of a machine be P. Suppose it depreciates at the rate of R% per annum. Then,

• Value of the machine after n years = • Value of the machine n years ago = • If A is R% more than B, then B is less than A by • If A is R% less than B, then B is more than A by Percentage Concepts & Tricks

A decimal fraction is one in which the denominator of the fraction is a power of 10 i.e. 10, 100, 1000 etc. The decimal fraction which has 100 as its denominator is know as Percentage. The numerator of such a fraction is known as Rate Per Cent.

Percentage Aptitude Question and Answer With Detailed ExplanationQuantitative Aptitude

## Percentage

 Question 1
What percentage of numbers from 1 to 30 has 1 or 9 in the unit's digit?
 A 12 B 15 C 20 D 22
Question 1 Explanation:
Explanation:
Such numbers from 1 to 30 are 1, 9 ,11, 19, 21, 29
Number of such numbers = 6
Required Percentage is ((6/20) * 100)% = 20%
 Question 2
A student erroneously multiplied a number by 2/5 instead of 5/2. What is the percentage error in the calculation?
 A 24% B 54% C 74% D 84%
Question 2 Explanation:
Explanation:
Let the number be 100, 2/5 of 100 is 40 while 5/2 of 100 is 250.
Now the difference is 210 on a base of 250.
Therefore, Percentage difference is 210/250 into 100 = 84%.
 Question 3
40 is subtracted from 60% of a number, the result is 50. Find the number?
 A 110 B 130 C 150 D 170
Question 3 Explanation:
Explanation:
(60/100) * x - 40 = 50
6x = 900
x = 150
 Question 4
In a factory, there are 40% technicians and 60% non-technicians. If the 60% of the technicians and 40% of non-technicians are permanent employees, then the percentage of workers who are temporary is?
 A 32% B 42% C 52% D 62%
Question 4 Explanation:
Explanation:
Total = 100
T = 40, NT = 60
40 * (60/100) = 24
60 * (40/100) = 24
24 + 24 = 48
100 - 48 = 52%
 Question 5
Juice is 15% costlier than water. By what percentage is the price of water lower than that of juice?
 A 5% B 6.50% C 9.50% D 13.05%
Question 5 Explanation:
Explanation:
Suppose, 1ltr water = Rs. 100
So, 1ltr juice will be Rs. 100 + (15% of 100) = 100 + 15= Rs. 115
Now, how would we express water as a percentage of juice?
(100/115) * 100 = 86.95%
 Question 6
Three candidates contested an election and received 1136, 7636 and 11628 votes respectively. What percentage of the total votes did the winning candidate get?
 A 57% B 60% C 65% D 90%
Question 6 Explanation:
Explanation:
Total number of votes polled =(1136 + 7637 + 11628) = 20400
Therefore, Required Percentage =((11628/20400) * 100)% = 57%
 Question 7
The population of a town increased from 1,75,000 to 2,62,500 in a decade. The average percent increase of population per year is:
 A 4.37% B 5% C 6% D 8.75%
Question 7 Explanation:
Explanation:
Increase in 10 years = (262500 - 175000) = 87500
Increase% = ((87500/175000) * 100)% = 50%
Therefore, Required Average = (50/10)% = 5%
 Question 8
A student has to obtain 33% of the total marks to pass. He got 125 marks and failed by 40 marks. The maximum marks are:
 A 500 B 600 C 800 D 900
Question 8 Explanation:
Explanation:
Given, that the student got 125 marks and still he failed by 40 marks
The minimum pass mark = 125 + 40 = 165
Given that minimum pass mark = 33% of the total mark
Total mark = 33/100 = 165
Total Mark = 16500/33 = 500
 Question 9
A stationery seller had some pens, sharpeners, erasers & pencils. He sells 65% of the total units and still has 175 units. Originally, he had:
 A 588 units B 400 units C 272 units D 500 units
Question 9 Explanation:
Explanation:
Suppose originally he had x units
Then, (100 - 65)% of x = 175
35/100x = 175
x = 500
 Question 10
Ankita is 25 years old. If Rahul's age is 25% greater than that of Ankita then how much percent Ankita's age is less than Rahul's age?
 A 40% B 35% C 10% D 20%
Question 10 Explanation: