Aptitude test : percentage shortcuts and tricks

Aptitude shortcut
In this post I describe some of the tricks of percentage calculation . 
by a certain percent , we means that many hundredths thus , x percent means x hundredths written as x% 






Fraction value of percentage :

1/2 = 50 %                   1/3 = 33.33%                      1/4 = 25%                     1/5 = 20 % 
1/6 =16.67%                1/7 = 14.28%                          1/8 =12.5%                1/9 = 11.11

Note :these fraction value helps to minimize the calculation

Formula:

  1. if the price of a commodity increases by R% , then the reduction in consumption so as not to increase the expenditure is 100*R/(100+R)%.
  2. if the price of a commodity decreases by R% , then the increases  n consumption so as not to decreases the expenditure is 100*R/(100-R)%.
  3. value of machine after n years = p(1-R/100)power n .
  4. if A is R% more than B , then b is less than A by 100*R/(100+R)%.
  5. if A is R% less than B , then b is more than A by 100*R/(100-R)%.

Example:

1. if 1/5 of a number is 25 less then 1/4 of a same number . what will be 3/2 of number .
ans.
                         as you know 1/5 = 20% and 1/4 = 25%
                         so difference b/w these two is 5% which is equal to 25 
                         then  5% *20  ---- 25*20     100% ----500
                        and 100% percent is the real value 
                        you can now calculate 3/2 so ans is    750

2. if the numerator of fraction is increase by 20% and denominator is decrease by 80% then fraction becomes 18/15. what is the actual fraction .

ans .                     120% N/20% D = 18/15
                             then N/D = (18/15 )*20/120
                             N/D = 1/5   answer

3 . if A's salary 20% less then B's salary then B's salary is how much more then A.

ans .                suppose B's salary is 100 then A's salary is 80
                        now you can calculate b's salary in respect to A
                      ( 20/80)* 100 = 25% is answer

4. A number is increased by 12% and again deceased by 18% then how much change in that value.

                   formula for this problem % change = (x)+(y)+x*y/100

Note take the value with symbol , if increase then take '"plus" if decease in value then take "minus". this formula is applicable for circle , square , triangle etc

                    12- 18 - 216/100 =   -8.16  decrease is value by 8.16% 



Related Posts:

  • SSC CGL 2014 praparation Algebra,Trigonometry and Number systems are very important part of SSC CGL Math Section. In recent paper of SSC  conventional questions from ratio-proportion, basic maths, time-speed-work are asked for namesake … Read More
  • Aptitude test : partnership shortcuts and tricks Partnership is an association of two or more persons who put their money together in order to carry on a certain business. It is of two kind: Simple  Compound Simple partnership: if the capitals of the partnership ar… Read More
  • Database quiz for IT officer exam As we all know,DBMS is very important subject for SO exam. For that reading book in detail is not possible,also its boring too. We are providing important question as a quiz 00:00:00 Start … Read More
  • Aptitude test : percentage shortcuts and tricks In this post I describe some of the tricks of percentage calculation .  by a certain percent , we means that many hundredths thus , x percent means x hundredths written as x%  Fraction value of percen… Read More
  • 10 quantitative aptitude tricks for Govt. exam Quantitative aptitude is the most common part of every exam . In this post I want to motivate you to solve the quantitative problem with the help of great videos. These videos are made by dif… Read More