FACTS  AND  FORMULAE  FOR  PERCENTAGE  QUESTIONS

 

 

I.Concept of Percentage : By a certain percent , we mean that many hundredths. Thus x percent means x hundredths, written as x%.

To express x% as a fraction : We have , x% = x/100.

Thus, 20% = 20/100 = 1/5;     

48% = 48/100 = 12/25, etc.

To express a/b as a percent : We have, ab=ab×100% .

 

Thus, 14=14×100%=25%

   

 

II. If the price of a commodity increases by R%, then the reduction in consumption so as not to increase the expenditure is R100+R×100%

If the price of the commodity decreases by R%,then the increase in consumption so as to decrease the expenditure is R100-R×100%

 

 

III. Results on Population : Let the population of the town be P now and suppose it increases at the rate of R% per annum, then :

1. Population after n years = P1+R100n

 

2. Population n years ago =  P1+R100n

 

 

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

1. Value of the machine after n years = P1-R100n

 

2. Value of the machine n years ago = P1-R100n

 

 

V. If A is R% more than B, then B is less than A by

R100+R×100%    

If A is R% less than B , then B is more than A by 

R100-R×100%  

Q:

3 is what percent of 5?

A) 45% B) 60%
C) 72% D) 80%
 
Answer & Explanation Answer: B) 60%

Explanation:

Here it is asked that 3 is what percent of 5

Let 3 is K percent of 5.

=> K x 5/100 = 3

=> K = 300/5 = 60

 

Hence, 3 is 60% of 5.

Report Error

View Answer Report Error Discuss

8 6109
Q:

Ramesh spent Rs. 38460 on the renovation of his home, Rs. 24468 on buying furniture and remaining 28% of the total amount he had as cash with him. What was the total amount ?

A) 87400 B) 92520
C) 88470 D) 90150
 
Answer & Explanation Answer: A) 87400

Explanation:

Let X be the total amount with Ramesh

Given 28% of X = Cash remaining

=> Amount spent = 72% of X = 38460 + 24468 = 62928

=> 72% of X = 62928

=>  X = ?

=> X = 87400

Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

9 6105
Q:

Arun’s weight is 140% of Akhil’s weight. Nani’s weight is 90% of Shreyon’s weight. Shreyon’s weight is twice as much as Akhil’s. What percentage of Arun’s weight is Nani’s weight?

A) 76% B) 77%
C) 78% D) 79%
 
Answer & Explanation Answer: C) 78%

Explanation:

Let Akhil's weight = p kg

=> Shreyon's weight = 2p kg

Nani's weight = 0.9 x 2p = 1.8p kg

=> Arun's weight = 1.4p kg

Required percentage = 1.4p1.8p x 100

= 77.8%

~= 78%

Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

8 6079
Q:

Express 6.72 % in ratio ?

A) 65 : 124 B) 42 : 625
C) 21 : 125 D) 37 : 442
 
Answer & Explanation Answer: B) 42 : 625

Explanation:

6.72/100 = 672/10000 = 42/625

Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

10 5993
Q:

At an examination in which maximum marks are 500. K got 10% less than L, L got 25% more than M and M got 20% less than N. If K got 360 marks what percentage of marks was obtained by N ?

A) 80 B) 87
C) 78 D) 76
 
Answer & Explanation Answer: A) 80

Explanation:

Let marks obtained by N = x

M's marks = 0.80x

L's marks = 1.25 (0.80x)

K's marks = (0.90) (1.25) (0.80x)

= 0.9x

But 0.9x = 360 ⇒ x = 400

Percentage of Marks obtained by N

= 400 x 100/500 = 80%

Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

7 5982
Q:

Last year vivek saved 10% of his annual earnings, this year he earned 5% more than last year and he saved 12% of his annual earnings. The amount saved this year was what percentage of the amount saved last year ?

A) 87% B) 98%
C) 138% D) 126%
 
Answer & Explanation Answer: D) 126%

Explanation:

Suppose total earnings = Rs. 10000
10% saving = 10000 x (10/100) = Rs. 1000
This year 5% more income than prev year = Rs. 10500
12% saving = 10500 x (12/100) = Rs. 1260
Percentage of amount saved = (1260/1000) x 100 = 126%

Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

4 5949
Q:

Twelve percent of Kalyan's monthly salary is equal to the sixteen per cent of Nandu's monthly salary. Sarnesh's monthly salary is half that of Nandu's monthly salary. If sarnesh's annual salary is Rs. 1.08 lacs, What is Kalyan's monthly salary ?

A) 15,000 B) 36,000
C) 24,000 D) 12,500
 
Answer & Explanation Answer: C) 24,000

Explanation:

Let K = Kalyan's monthly salary
N = Nandu's monthly salary
S = Sarnesh's monthly salary.
Then from given data,
12% of K = 16% of N
S = N/2 => N = 2S
K = 16/12 x N = 16/12 x 2S
= 16/6 x 1.08/12 = 16/6 x 0.09 = 0.24 lacs = 24,000

Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT , GATE , GRE
Job Role: Bank Clerk , Bank PO

4 5934
Q:

Prashanth sold a album for $ 735 and made a profit of 22.5% . The cost price of the album went up by $120 and so Prashanth increased the selling price by $120. What is his profit % now ?

A) 19.32 % B) 18.75 %
C) 21.41 % D) 22 %
 
Answer & Explanation Answer: B) 18.75 %

Explanation:

Prashanth sold a album for $ 735 and made a profit of 22.5% .
CP = 735 x 100/122.5 = Rs. 600
New CP = 600 + 120 = Rs. 720
New SP = 735 + 120 = Rs. 855.

Profit = Rs. 135.

profit % = 100 x 135/720 = 18.75%.

Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

2 5903