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 breadth =110
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