Decrease Percent

When a quantity shrinks (gets smaller), then we can compute its Decrease Percent:

( Original amount - New amount) Decrease %= ----------------------------------- x 100                               Original amount

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

Examples :

1) Find the decrease % of a) $80 to $60 b) $155 to $130

a) $80 to $60
Solution :
Original amount= $80
Net amount = $60

( Original amount - New amount) Decrease %= ----------------------------------- x 100                               Original amount

( 80 - 60) Decrease %= ------------ x 100                          80

= (20/80) x 100

= 0.25 x 100

So, Decrease % = 25

_________________________________________________________________
b) $155 to $130
Solution :
Original amount= $155
Net amount = $130

( Original amount - New amount) Decrease %= ----------------------------------- x 100                               Original amount

(155 - 130) Decrease %= ------------ x 100                        155

= (25/155) x 100

= 0.16129 x 100

So, Decrease % = 16.129

_________________________________________________________________
2) On Sunday 845 people went to the Zoo. On Monday only 169 people went. What is the per cent decrease in the people visiting the Zoo on Monday?

Solution :
Original amount = 845

New amount = 169

( Original amount - New amount) Decrease %= ----------------------------------- x 100                               Original amount

( 845 -169) Decrease %= --------------- x 100                        845

= (676/845) x 100

= 0.8 x 100

So, Decrease % = 80

_________________________________________________________________
3) A man got 10% decrease in purchasing a machine . If the new price of the machine was $3000, find the original price of the machine.

Solution :
Decrease % = 10

New amount = $3000

Let original amount be $p.

( Original amount - New amount) Decrease %= ----------------------------------- x 100                               Original amount

( p - 3000) 10 %  = ---------------------- x 100                         p

Cross multiply

10p = (p - 3000) x 100

10p = 100p - 300,000

10p-100p = -300,000

-90p = - 300,000

So, p = 300,000/90 p = $3333.33

---

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

Home Page