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:

A businessman imported Laptops, worth Rs 210000, Mobile phones worth Rs 100000 and Television sets worth Rs 150000. He had to pay 10% duty on laptops, 8% on Phones and 5% on Television sets as a special case. How much total duty (in Rupees) he had to pay on all items as per above details?

A) 36500 B) 37000
C) 37250 D) 37500
 
Answer & Explanation Answer: A) 36500

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

0 1067
Q:

The rate of simple interest for which a sum of money becomes 5 times in 8 years is

A) 30% B) 40%
C) 50% D) 55%
 
Answer & Explanation Answer: C) 50%

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

1 1065
Q:

A shopkeeper marks up his wares by 60% and offers 25% discount. What will be the selling price (in Rs) if the cost price is Rs 1600?

A) 1920 B) 2000
C) 2120 D) 2200
 
Answer & Explanation Answer: A) 1920

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

2 1065
Q:

A man spends 15% of his income. If his expenditure is Rs. 75, his income (in rupees) is:

A) 400 B) 300
C) 750 D) 500
 
Answer & Explanation Answer: D) 500

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

1 1061
Q:

Weight of A and B are in the ratio 11 : 8. A’s weight increases by 40% and the total weight of A and B increases by 30%. What is the percentage increase in the B’s weight?

 

 

 

 

A) 10.25 B) 16.25
C) 12.5 D) 18.75
 
Answer & Explanation Answer: B) 16.25

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

2 1057
Q:

The marked price of a pen is Rs 3000. The shopkeeper gives two successive discounts of 15% and a% to the customer. If the customer pays Rs 2142 for the pen, then what is the value (in percentage) of a?

 

A) 16   B) 14  
C) 18   D) 17
 
Answer & Explanation Answer: A) 16  

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

2 1056
Q:

If 7/8th of 5/4th of a number is 315, then 5/9th of that number is _____

A) 123 B) 81
C) 140 D) 160
 
Answer & Explanation Answer: D) 160

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

0 1054
Q:

When a number is increased by 26, it becomes 113% of itself. What is the number?

A) 200 B) 312
C) 390 D) 234
 
Answer & Explanation Answer: A) 200

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Percentage
Exam Prep: Bank Exams

0 1054