# Percentage for bank exams – PO, Clerk, Specialist Officer

##### Percentage for bank exams – PO, Clerk, Specialist Officer

Type 1: In that type of questions we ask percentage increase/decrease. So to solve these type of questions we only know two formula:-

1. Percentage increase= (Actual increase/ Original quantity) x 100

2. Percentage decrease= (Actual decrease/ Original quantity) x 100

Example:-

If the production of rice went up from 225 MT in 1993 to 242 MT in 1994 then the percentage increase in rich production from 1993 to 1994.

Solution:-

Actual Increase = 242 – 225 =17 MT

Percentage Increase = (17/225) x 100 = 7 x 5/9

ANS:- 7 x (5/9)

Type 2: Successive Percentage change

If there are successive increase of P%, Q%, & R% in 3 stages then the effecitive percentage increase is

(((100+P)/100) x ((100+Q)/100) x((100+R)/100) -1) x 100

If asked for successive decrease then put – instead of + in above formula.

i.e (((100-P)/100) x ((100-Q)/100) x((100-R)/100) -1)X100

The above formula can be generalize.

Example: The population of a city increase by 20% every year. If the present population of city is 432000. What was the population of the city two year ago?

Solutions:

120/100 x 12/100 x X = 432000

So, X= 300000.

Example: The length of rectangle increases by 15% and breadth by 10%. What is the consequent increase in area?

Solutions:

New length = 115

New Area = 115 x 110 = 12650

Old Area = 10000

Increase % area = 12650-10000/10000 = .265 x 100 = 26.5%

Type3:

For that type of question we have remember only this formula;

Price x Cost = Expedience

Example: If the price of rice rises by 20% by what percentage should a family reduce the consumption in order to spend the same amount as before.

Solutions:

Price x Cost = Expenditure

Old        100 x 100 = 10000

New      120 x X = 10000

X= 83.33%

100- 83.33 = 16.67%

Example: If the price of diesel rises by 60% how much the consumption decrease of that expendence also increase by 60%

Solutions:

Price x Cost = Expenditure

Old        100 x 100 = 10000

New      160 x X = 16000

X= 100%

So, Percentage consumption  decrease= 0%

Example: When the price of rice rises by 10% and its consumption is decrease by 8%. Find percentage change in expenditure.

Solutions:

Price x Cost = Expenditure

Old        100 x 100 = 10000

New      110 x 92 = 10120

Percentage Change = (Final – Initial) / Initial  x 100

= ((10120 – 10000) / 10000) x 100

= 120/10000 x 100 = 1.2 % Increase

Type 4 : These contains random type of questions that are frequently asked in examination with short tricks.

1. If in question what percentage of P’s quantity is Q’s then quickly apply this formula:-

X% of P = Q

and find X.

Example: The second and third terms are 20% and 80% more than the first. What percentage of second term is the third

Solutions:

Let first term = 100

then second term = 120

and third term = 180

X% of 120=180

X= 180/120 x 100 = 150

Example:Anil spend 40% of his income  on the rent, 30% of the remaining on medical, 20% of the remaining on education . If he save Rs 820every month find its monthly salary

Solutions:

Let salary = 100

then  RS 40 is spend on rent

and remaining = 60

60x 30 /100 = 18

remaining = 42

42 x 20/100 = 8.4 spend

total  spend = 40+18+8.4 = 66.4

Remaining = 100 – 66.4 = 33.6

33.6/ 100 x X = 840

X = Ans