Percentage - Steps to solve percentage problems and solved questions

Percentage 

Percentage literally means per Cent or Per 100. In percentage, we convert the fraction, such that the denominator becomes 100. It is used to compare fraction as we have to convert all the fractions to a single denominator i.e. 100.

Let say we have to compare two fractions  7/10   and 6/9. To do this comparison either we take LCM and then make the denominator of each equal to LCM. Or we can simply convert them to denominator 100  by use of percentage and then we can compare them.
 
  Now taking 7/10 and converting it percentage, we have (7/10) x 100  = 70 %
           and converting 6/9 to percentage , we have (6/9) x 100 =   66.67 %

It is clear now that  7/10    >  (6/9) .It is easier than use of LCM to compare them.

Percentage have a wide area of use from schools to managements decisions, scientific applications, data interpretation and so on.

Percentage Formula

Percentage =  fraction x 100

the fraction could be any ratio, marked scored against total marks, run scored against ball faced, energy used against total energy and so on.

Converting a decimal to percentage

Percentage = Decimal x 100

Expressing a quantity as a percentage on another quantity.

Lets say we have to express x as percentage of another quantity y

then the formula is  (x/y) x 100

Expressing the increase and decrease of a quantity in percentage

If  |x| is the absolute increase or decrease in the value of a quantity say 'y' then the percentage increase or decrease is expressed as

   absolute percentage change = { |x|/y } x 100

where the sign of x will determine the increase or the decrease in value.

Expressing percentage as a fraction

Let us say the percentage change is x %, then the corresponding fraction is

Fraction = x/100 i.e. just divide the x by 100 to get the corresponding fraction.