**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 Explanation** – Quantitative Aptitude

## Percentage

Question 1 |

12 | |

15 | |

20 | |

22 |

**Answer: Option C**

__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 |

24% | |

54% | |

74% | |

84% |

**Answer: Option D**

__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 |

110 | |

130 | |

150 | |

170 |

**Answer: Option C**

__Explanation:__

(60/100) * x - 40 = 50

6x = 900

x = 150

Question 4 |

32% | |

42% | |

52% | |

62% |

**Answer: Option C**

__Explanation:__

Total = 100

T = 40, NT = 60

40 * (60/100) = 24

60 * (40/100) = 24

24 + 24 = 48

100 - 48 = 52%

Question 5 |

5% | |

6.50% | |

9.50% | |

13.05% |

**Answer: Option D**

__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 |

57% | |

60% | |

65% | |

90% |

**Answer: Option A**

__Explanation:__

Total number of votes polled =(1136 + 7637 + 11628) = 20400

Therefore, Required Percentage =((11628/20400) * 100)% = 57%

Question 7 |

4.37% | |

5% | |

6% | |

8.75% |

**Answer: Option B**

__Explanation:__

Increase in 10 years = (262500 - 175000) = 87500

Increase% = ((87500/175000) * 100)% = 50%

Therefore, Required Average = (50/10)% = 5%

Question 8 |

500 | |

600 | |

800 | |

900 |

**Answer: Option A**

__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 |

588 units | |

400 units | |

272 units | |

500 units |

**Answer: Option D**

__Explanation:__

Suppose originally he had x units

Then, (100 - 65)% of x = 175

35/100x = 175

x = 500

Question 10 |

40% | |

35% | |

10% | |

20% |

**Answer: Option D**

__Explanation:__

Percentage decreased = (25/125) * 100 = 20%