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:

 83% of 2350 = ?

A) 1889.95 B) 1912.35
C) 1875.25 D) 1950.50
 
Answer & Explanation Answer: D) 1950.50

Explanation:
83% of 2350 = ?
 
83/100 x 2350
 
=8.3 x 235
 
=1950.50
Report Error

View Answer Report Error Discuss

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

12 4679
Q:

40% of 80?

A) 36 B) 32
C) 42 D) 44
 
Answer & Explanation Answer: B) 32

Explanation:

Here 40% of 80 is given as

40100 x 80 = 8 x 4 = 32

Report Error

View Answer Report Error Discuss

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

7 4665
Q:

If P is 140, which is 40% more than Q, then 3/25 of Q is

A) 9 B) 12
C) 18 D) 24
 
Answer & Explanation Answer: B) 12

Explanation:

From the given data,

P = 140

But it is given that,

40% of Q + Q = 140 = P

=> Q + [40Q/100] = 140

=> [100Q + 40Q]/100 = 140

=> 140Q = 140 x 100

=> Q = 100

Now,

 3/25 of Q 

= (3/25) x 100

= 3 x 4 

= 12 

 

Required 3/25 of Q  = 12.

Report Error

View Answer Report Error Discuss

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

25 4657
Q:

Mohan spends 23% of an amount of money on an insurance policy, 33% on food, 19% on children’s education and 16% on recreation. He deposits the remaining amount of Rs. 504 in bank. How much amount does he spend on food and insurance policy together?

A) Rs. 2326 B) Rs. 5876
C) Rs. 1741 D) Rs. 3136
 
Answer & Explanation Answer: D) Rs. 3136

Explanation:

Let total amount = Rs. P

Total expenditure = (23 + 33 + 19 + 16)% of P = 91%ofP

Remaining money = (100 - 91)% of P = 9% of P

But given in the question that,

9% of P = 504

9p/100 = 504

=> P = 50400/9

=> P = Rs. 5600

 

Required money spent on Food & Insurance = 23 + 33 %

= 56% of 5600

= 56 x 5600/100 = 56 x 56 = Rs. 3136

Report Error

View Answer Report Error Discuss

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

5 4638
Q:

The price of pulses has increased by 25%. The percentage of reduction that a family should effect in the use of pulses so as not to increase the expenditure on this account is ?

A) 16% B) 20%
C) 84% D) 72%
 
Answer & Explanation Answer: B) 20%

Explanation:

Reduction in consumption
= P100+P X 100%
= 25100+25 X 100%
= 20%

Report Error

View Answer Report Error Discuss

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

4 4528
Q:

The tax on an article decreases by 10% and its consumption increases by 10%. Find the effect percent on its revenue?

Answer

-10+10-10*10100  % = -1%


 


\inline \therefore Decrease in revenue = 1%

Report Error

View answer Workspace Report Error Discuss

Subject: Percentage Exam Prep: Bank Exams

13 4461
Q:

Three strategies P, Q and R have been initiated for cost cutting in a company producing respectively 20%, 30% and 10% savings. Assuming that they operate independently, what is the net saving achieved ?

A) 49.6% B) 50.4%
C) 33.67% D) 66.66%
 
Answer & Explanation Answer: A) 49.6%

Explanation:

As these three strategies P, Q and R are independent so these will cut cost one after the other.
If initial cost is Rs 100, then
20% cost is cut after initializing strategy P, then cost will remain 80% = 80
further 30% cost is cut after strategy Q, then cost will remain 70% of 80 = 56
further 10% cost is cut after strategy R, then cost will remain 90% of 56 = 50.4

Thus final cost remains 50.4 % of the original cost. Hence net saving is 100 - 50.4 = 49.6 %.

Report Error

View Answer Report Error Discuss

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

3 4410
Q:

Two candidates fought in a municipality election. One of them got 54% of the total votes pooled and won by 1080 votes. What was the total number of votes polled ?

A) 12000 B) 13500
C) 15400 D) 11000
 
Answer & Explanation Answer: B) 13500

Explanation:

Given in municipality election 54% votes have won by 1080

 

Let the total number of votes be x.

 

 54x100 - 46x100 = 1080

 

8x = 108000

 

x = 13,500

 

Therefore, total number of votes = 13,500.

Report Error

View Answer Report Error Discuss

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

7 4401