Mathematics Trick for Percentage - PA Exam 2014

PERCENTAGE CHAPTER MATHS TRICKS

Basically on previous article we provide the profit and loss and work and time tricks now, we are provide percentage chapter of maths that is very useful in all exams and 8-10 no. of question are asked from that chapter. 

With the help of percentage tricks we can apply is to the various form like ratio, profit loss, time and distance, graphs, pie chart etc these are basically are the form of percentage and if you clear the basic concept it will be beneficial in many ways.

so, first what is percentage  

DEFINITION 

a percentage is a number or ratio expressed as a fraction of 100.
if we have to convert percentage into fraction than it is divide by 100.

Example 1 :- if we write 45% then its equal to 45/100 or in fraction 9/20 or in decimal 0.45
if we have to convert fraction into percentage we have to multiple with 100.
Example 2 :- if we write 3/5 in fraction it is equal to 60%
                                    3/5x100=60.

READ AND LEARN FOLLOWING TABLE as also known as conversion table of percentage. Learn this table it help you a lot to solve many problem.

the following fraction in red colour are MOST IMPORTANT.

Fraction	Percentage
1/1	100%
1/2	50%
1/3	33.33%
1/4	25%
1/5	20%
1/6	16.66%
1/7	14.28%
1/8	12.5%
1/9	11.11%
1/10	10%
1/15	6.66%
1/20	5%
1/25	4%
1/30	3.33%
1/40	2.5%
1/50	2%
1/60	1.66%
1/75	1.33%
1/80	1.25%
1/90	1.11%
1/100	1%

by this conversion table we can change fraction into percentage and percentage into fraction

EX:- if we have to find 2/5 in %?

In the table we know that 1/5=20%
then, if we multiply both by 2
then we have 1/5x2 = 2x20%
answer is 2/5 = 40%
so, you only to know basic fraction and percentage that given above.

in the inverse 
Ex. If we have to find out 1/15 fraction in percentage%?

In the table we have 1/5 = 20%

then both side multiple by 1/3

we get 1/15 = 6.66%

SOME BASIC QUESTION THAT IS ALWAYS ASKED IN THE EXAMS

TYPE 1. 
if there is increase of X% and subsequently X% decrease then there is always loss / decrease in the condition.

ex. If rohan salary is increase by 50% and subsequently decrease by 50%. How much percentage loss?

ans. By trick ----  50x50/100= 25% decrease/loss

TYPE 2.
if A is P% more than B. then B is less than by A 
 with P/(100+P)x100

ex. If radha earning is 25% more than sita. Then sita earning is how many percentage less then by radha?ans. By trick ---- 25/(100+25)x100=20%  

TYPE 3.

If A is P% less than B. then B is more than by A
 with P/(100-P)x100

ex. If golu age is 20% less than gita than gita age is how many percentage more than golu?
ans. By trick ---- 20/(100-20)x100=25%

TYPE 4.
if there is p% increase in price . how much % decrease his consumption so that his expenditure on it does not change. 
formula P/(100+P)x100

ex. If petrol price increase by 25%. How much percentage a person reduced his consumption so that his expenditure on it does not increase?
ans. 25/(100+25)x100=20%

TYPE 5. 
if there is p% decrease in price . how much % increase his consumption so that his expenditure on it does not change.
formula P/(100-P)x100
ex. If there is 30% decrease in eggs price. How much a person increased his consumption so that his expenditure on it does not increase?

ans. 30/(100-30)x100=42.85

TYPE 6.

Ex. If suman need 36% minimum mark to passed a exam but she score 24% mark and fail by 9 marks. What is the total mark?

ans. Difference in % = difference in mark

In that 36%-24%=12%
that is 12%=9marks
so, total mark = 9/12x100= 75