Percentage

Percentage

A fraction which has 100 as its denominator is known as a Percentage.

Decimal to Percentage

Multiply decimal by 100%

0.27 = 0.27 × 100% = 27%

1.27 = 1.27 × 100% = 127%

0.027 = 0.027 × 100% = 2.7%

Percentage to Decimal

Divide percentage by 100

27% = 27/100 = 0.27

127% = 127/100 = 1.27

2.7% = 2.7/100 = 0.027

Decimal and Percentage - Interactive

Percentage Change

Percentage Change = (change/original) x 100%

The price of an item is increased from $90 to $108. Find the percentage increase in price.

Change in price = 108 – 90 = 18

Percentage Change = (18/90) x 100% = 20%

Comparing Quantities

To convert one quantity as a percentage of another quantity both must be in same units.

A = 100 g

B = 1kg = 1000 g

A as percentage of B = (100/1000) x 100% = 10%

B as percentage of A = (1000/100) x 100% = 1000%

Percentage Increase or Decrease

Take the given quantity as 100%, to increase or decrease it by a given percentage.

Increase 250 g by 10%

100% --> 250 g

110% --> (250/100) x 110 = 275 g

Decrease 250 g by 10%

100% --> 250 g

90% --> (250/100) x 90 = 225 g

Increase 3 km by 20%

100% --> 3 km

120% --> (3/100) x 120 = 3.6 km

Decrease 3 km by 20%

100% --> 3 km

80% --> (3/100) x 80 = 2.4 km

Percentage - WORD Problems

Ahamed has 10% as much money as Babu.

Babu has 30% as much money as Carol.

How many percent money does Ahamed have as Carol?

Let us change percentage to units

Ahamed : Babu = 1 unit : 10 units

Babu : Carol = 3 parts : 10 parts

Let us change all to x and Make Babu's Money Equal

Ahamed : Babu

= 3(1x) : 3(10x)

= 3x : 30x

Babu : Carol

= 10(3x) : 10(10x)

= 30x : 100x

Ahamed : Babu : Carol = 3x : 30x : 100x

Ahamed have 3% money as much as Carol.

A shopkeeper bought a TV for $800 and sell it at a profit of 20%.

(a) Find the selling price of the TV.

(b) At the Year End Sale, this TV is sold at a discount of 10%. Find the selling price of the TV during Year End Sale.

(a) Cost Price = 100% --> $ 800

Selling price = 100% + 20% = 120%

120% --> (120/100) x $800 = $ 960

(b) Selling Price = 100% --> $ 960

Discounted price --> 100% - 10% --> 90%

90% --> (90/100) x $960 = $864