Increase Percent 

When a quantity grows (gets bigger), then we can compute its Increase Percent:

                           ( New amount - Original amount)
Increase Percent= ------------------------------- x 100
                               Original amount

Note: When you compute percent increase you always compare how much a quantity has changed to the original amount.

The numerator in these formulas is always a POSITIVE number
(or zero, if the quantity doesn't change at all).

Examples :

1) The size of a bag that could hold 5 kg of sugar has now been increased so that it can hold 6kg. What is the percentage increase in size?

Solution :
Old Capacity of the bag = 5 kg

New capacity of the bag = 6 kg.

                           ( New amount - Original amount)
Increase Percent= ------------------------------- x 100
                               Original amount
∴ Increase % = [( 6 – 5 ) / 5] x 100

= ( 1 / 5) x 100

= 20 %

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2) The salary of a bank clerk was increased by 7%. If his present salary is $8,025. What was it before increment?
Solution :

Let the salary before increment be ‘a’ .

                           ( New amount - Original amount)
Increase Percent= ------------------------------- x 100
                               Original amount
7 = [( 8025 – a )/ a ] x 100

7 x a = ( 8025 – a ) x 100 [ cross multiply ]

7a = 802,500 – 100 a

∴ 7a + 100a = 802,500

107a = 802,500

∴ a = 802,500 / 107

Salary before increment = $7500.

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3) Your friend diets and goes from 125 pounds to 200 pounds. What was her percentage weight gain?
Solution :
Original weight = 125 pounds
New weight = 200 pounds
As the weight increase so here we use increase % formula.
                           ( Original amount - New amount)
Increase Percent= ------------------------------- x 100
                               Original amount
Decrease % = [( 200 - 125)/ 125 ]x 100
= (75 / 125 ) x 100
= (3/5) x 100
= 300 /5 = 60 %
So, she gained her weight by 60 %.


Percentage

Conversion of Percentage to Fraction
Conversion of Fraction to Percent
Conversion of Percentage to Decimal
Conversion of Decimal to Percent
Find the Percentage of a given number
What Percent is one number of another number
Percentage as a comparison of two quantities
Increase Percent
Decrease Percent

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