Percentage
Formulas of Percentage
Percentage means for every hundred.
The symbol % must be replaced by a fraction 1/100. A percentage must be
expressed as a fraction or a decimal.
Ex: 24% = 24/100 = 6/25 or 0.24
1) a is what percent of b?
what % is a of b?
what % of b is a? sol: a/b x 100
To calculate percent the example problem is given below.
Ex: 50 is what percentage of 100
Sol: (50/100) x 100 = 50%
2) If a is greater than b, then interms of % , a is more than b by (a-b)/b x 100
If a is less than b then interms of % , a is less than b by (b-a)/b x 100
3) If a% and b% are two successive changes, then the overall change = a+b+(ab)/100%
Note: Use '+' for increase and '-' for decrease
4) % of increase = (Increase/Initial value) x 100
% of decrease = ( Decrease/Initial value) x 100
Percentage Introduction and Shortcut
The videos explains basics of percentage and shortcuts. You can calculate percentage problem on your finger tips. You will save your time in your bank exams. If you practice well and you can solve the problems within 45 seconds. Dollar symbol contained in the video. So, to leave the symbol and practice the problems.
Problems of Percentage
1) What percentage of 70 is 28?
Sol:
The problem means 28 is how much percent in 70 so we have to calculate percent for every hundred
Percentage = 28/70 x 100 = 40%
2) 60 is what percent of 240?
Sol: 60/240 x 100 = 25%
3) 24% of 450 = 12% of 'a' then what is value of 'a'?
Sol: 24/100 x 450 = 12/100 x a
a = (24 x 450)/12 = 900 :-( both 100's are cancelled)
4) 40% of a number is 160 then 32% of it is?
Sol 1: Lets take the number as 'a'
40/100 x a = 160
a = (160 x 100)/40 = 400
So 32% of a = 400 x 32/100 = 128
Sol 2: 40% of number = 160 then
32% of number = ?
32/40 x 160 = 128
5) A number decreased by 20% gives 72 the number is?
Sol: 100% of a number decreased by 20% then the number is 80%
Lets take the number as 'a'
80% of 'a' = 80/100 x a = 72
'a' = (72 x 100)/80
= 90
6) 30% of a number when added to 77 the result is the number itself. the number is?
Sol: Lets take the number as 'a'
30/100 x a +77 = a
(30a + 7700)/100 = a
30a + 7700 = 100a
70a = 7700
a = 7700/70 = 110
7) madhu saves 7% of his income. what is his expenditure if his income is rs.11,400?
Sol: Less the savings in income the expenditure is 93%
expenditure = 93/100 x 11,400
= 10602
8) In a school 8% of the students failed in exam what is the number of students passed in the exam if 1600 appeared for it?
Sol: Passed students = 92/100 x 1600 = 1472
9) Madhu spends 11% on house rent, 18% on kids education, 21% for food, 16% on clothes and 5% on
transport. What is his monthly savings if his income is 13000?
Sol: calculate all his expenditures = 11+18+21+16+5 = 71%
Less the expenditure from his income. So the savings is 29%
Savings = 29/100 x 13000 = 3770
10) 'A' is 25% more than 'B' by how much percent 'B' is less than 'A'?
Sol: lets the value of 'B' is 100% the value of 'A' is increased 100% to 125%
Difference between 'A' and 'B' is 25%
'B' s reduced percent than 'A' = (Difference/Value of 'A') x 100
= 25/125 x 100 = 20%
11) The price of phone is less than the price of the bag by 20% what % the price of bag is more than
the price of phone?
Sol: Lets take price of bag is 100% then price of phone is 80%
Difference between price bag and price of phone is 20%
The price of bag more then price of phone = 20/80 x 100 = 25%
12) Two numbers are 25% and 40% less then the third number. By how much percentage the first
number more then the second number?
Sol: If you take third number as 100%, the first number is 75%, the second number is 60%.
Lets find First number is more then the second number
in percentage = 15/60 x 100 = 25%
13) A dealer marks his goods 20% above cost price He then allowed some discount on it and marks a profit of 12% . What is the rate of discount?
a) 6 2/3
b) 6 1/4
c) 33 1/3
d) 16 2/3
c) 33 1/3
d) 16 2/3
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