Percentage

Percentage

Percent Convert into Fraction :

5% = 5/100 = 1/20

Fraction Convert into Percent:

1/20 = (1/20)*100 = 5%

To find the percent increase of number:

% increase = [{(New Value - Old Value)/Old value}*100] %

Example : The Population of a village in 1980 was 3000 & in 1990 was 3200. Find the percent increase in population.

Solution : = [{(New Value - Old Value)/Old value}*100] % 

                 = {(3200 - 3000)/3000}*100

                 = (200 /3000) * 100

                 = 20/3 

                 = 6 integer (2/3) %

To find the percent decrease of number:

% increase = [{(Old Value - New Value)/Old value}*100] %

Example : The cost of a bike last year was Rs. 19000 & in this year is Rs. 17000. Find the percentage decrease in it's cost.

Solution : = [{(Old Value - New Value)/Old value}*100] %

                 = {(19000 - 17000)/19000}*100

                 = (2000 /19000) * 100

                 = 200/19 

                 = 10 integer (10/19) %

If the price of a commodity increased by R% then How much % decreased it's consumption. So as not to increase the total expenditure.

    OR

If A's income is R% more than that of B. Then, B's income How much % less than that of A.

= [R/(100+R)] * 100 

Example : If A's income is 30% more than that of B. Then, B's income How much % less than that of A.

Solution : = [R/(100+R)] * 100

                = [30/(100+30)] * 100

                = (30/130) * 100

                = 300/130

                = 23 integer (1/13) %

If the price of a commodity decreased by R% then How much % increase it's consumption. So as not to decrease the total expenditure.

    OR

If A's income is R% less than that of B. Then, B's income How much % more than that of A.

= [R/(100-R)] * 100 

Example : If A's income is 15% less than that of B. Then, B's income How much % more than that of A.

Solution : = [R/(100-R)] * 100

                = [15/(100-15)] * 100

                = (15/85) * 100

                = 300/17

                = 17 integer (11/17) %

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Questions : 

Example : 64% Convert into Fraction :

Solution  : 64% = 64/100 = 16/25 

Example : 3/7 Convert into Percent:

Solution  : 3/7 = (3/7)*100 = 300/7% = 42 integer (6/7) %

Example : What % is 120 of 90 ?

Solution  : =(100*120) / 90 = 400/3% = 133 integer (1/3) %

Example : An Ore contents 14% Copper. How many Kg. of the Ore are required to get 77 Kg. Copper.

Solution : Ore - 100 Kg

                 Copper 14 %  - 14 Kg.

                 14 Kg Copper in used 100 Kg of Ore

                 77 Kg Copper in used = ? Kg of Ore

                   

                 = (100*77) / 14

                 = 550 Kg.