Featured post

SSC Recruitment 2017 | Vacancy Details | Notification of CGL CHSL

SSC Announced the Calendar for CGL 2017 and the SSC CGL 2017 Notification is going to release in the month of March for SSC Recruitment 2...

Sponsored Link

Thursday, 28 January 2016

Maths Shortcut Tricks to Solve Percentage Problems for SSC CGL Exams 2017

Maths Tricks for Competitive Exams 2016 and Latest Maths Formulas for SSC CGL 2016-2017. Important Maths Tips and Tricks for SSC CGL 2017. Follow FlizzIndia for Latest GK and Current Affairs. Free Online Test Series for Upcoming Competitive Exams.


1. If the value of something is increased by x % and again increased by y % then resulting effect in percent
Total change = {x+y+x*y/100}
Example :
The Salary of a worker is first increased by 10% and thereafter increased by 5%. What is the overall change in percent.
Solution:
overall change = + 10 + 5 + (+10)(+5)/100 = +15.5 % (increased)
use (+) sign for increment and (-) sign for decrement.
2.If the value of something is increased by x % then decreased by y % then resulting effect in percent
Total change = {+x- y+ (x*(-y)/100)}
Example :
The Salary of a worker is first increased by 10% and thereafter decreased by 5%. What is the overall change in percent.
Solution:
overall change = + 10 – 5 +(10)(-5)/100 = +4.5 % (increased)
use (+) sign for increment and (-) sign for decrement.
3.If the value of something is decreased by x % and again decreased by y % then resulting effect in percent
Total change = {-x – y + (-x)*(-y)/100}
Example :
The Salary of a worker is first decreased by 10% and thereafter decreased by 5%. What is the overall change in percent.
Solution:
overall change = – 10 – 5+ (-10)(-5)/100 = -14.5 % (decreased)
use (+) sign for increment and (-) sign for decrement.
Now, this is just the formula but its application are endless in the question of percentage , for the questions like-
1. If both the lengths (%) and breadth(%) of a rectangle are changed find the change in area(%) ?
2. If the speed and time of a vehicle are changed, find the change in distance ?
Similarly in all those questions where two quantities are multiplied to produce third one
rate * time = cost
efficiency * time = work
average * no. of elements = total value
rate * quantity = price (expenditure)

No comments:

Post a Comment

Related Posts Plugin for WordPress, Blogger...