Percentage questions are asked in many competitive examination including all of SSC, IBPS, class 5, class 6, class 7, class 8, class 9, class 10 etc. exams. Sometimes it is very time consuming to solve percentage questions. To score more in competitive exams and other exams, a candidate has to solve questions as quickly as possible. That is why the need of shortcut tricks arise. So here are some Percentage Formula Shortcut Tricks with questions and solutions which will let you solve percentage questions quickly and easily.
trick #1
If A’s income is x% more than B’s income, then how much per cent B’s income is less than that of A’s.
Shortcut percentage formula for above question = [x/(100+x)]*100 %
Suppose you are given a question like the one given below.
If A’s income is 25% more than B’s income, then how much per cent B’s income is less than that of A’s.
Shortcut formula for percentage questions like the one given above:
B’s income will be less by = [25/(100+25)]*100 %
(25/125)*100= 20%
trick #2
If A’s income is x% less than B’s income, then how much per cent B’s income is more than that of A’s.
Shortcut percentage formula for above question = [x/(100-x)]*100 %
Here is an example:
If A’s income is 20% less than B’s income, then how much per cent B’s income is more than that of A’s.
Shortcut formula for percentage questions like the one given above:
B’s income will be less by = [20/(100-20)]*100 %
(20/80)*100= 25%
trick #3
If the sides of any 2 dimensional figure e.g. circle, square, rectangle, triangle etc. are increased by x%, then its area will increase by
2x+[(x^2)/100]
Here is an example:
If the sides of a square are increased by 30%, then find the percentage increase in its area?
Putting the above formula:
Percentage increase in area of square = (2*30)+[(30*30)/100]
=60+(900/100)
=69 %
So the area of the square will increase by 69%.
Trick #4
Q: the salary of a person was first increased by 20 percent and then it is decreased by 5%. Find the change in his salary.
Shortcut trick:
Suppose x= percentage increase
And y= percentage decrease
Then change in salary= x-y-(xy/100)
So applying the above percentage formula
Change in salary = 20-5-[(20*5)/100]
15-(1)= 14 %
Since the sign comes out to be positive, it indicates an increase in salary.
But if the sign comes out to be negative, it indicates a decrease in salary.
This article is originally published by ExamFormIndia.in.