How do you work out the original cost of a product given the new cost and the discount?
July 1st, 2009 | by admin |
andyrobsmith asked:
Lets say that we see a product in a shop. It says that it now costs £70 after a 30% discount.
Lets say that we see a product in a shop. It says that it now costs £70 after a 30% discount.
How would you work out the original cost?
With the above example it is easy, through a method of trial and error we can quickly come up with the original cost.
Does anyone know the proper method or equasion to use to work it out?
SEAN
6 Responses to “How do you work out the original cost of a product given the new cost and the discount?”
By Joe K on Jul 3, 2009 | Reply
p = orig price
p - .3p = 70
p ( 1 - .3) = 70
p = 70 / (1 - .3)
p = 100
By genius on Jul 4, 2009 | Reply
let x be original cost.r be rate of discount
new cost= x-discount=x - x*r/100
=x(1-r/100)
x=newcost/(1-r/100)
got it?
By fordest on Jul 5, 2009 | Reply
The easiest way is to use porportions.
You are paying 70% so
Always put the % paid over one hundred.
and the Discounted price over the original price
70/100=70/x
Cross mulitpy. 30x=7000
Solve for x
x=100 pounds
By nysenutz on Jul 8, 2009 | Reply
OK …subtract the discount percentage from 100. divide the new cost by the answer. Mutiply in by 100, and thats your original cost. BE aware that most retailers put a minimum of 100% mark up…so if they buy something for $50 they will sell in for $99.99. (say $100), therefore , after the 30% discount they are still making $20 on the sale.
By reg on Jul 8, 2009 | Reply
new price = old price - (old price * discount rate)
70 = op - 0.3op
70 = op (1-0.3)
70 = op (0.7)
op = 70 /0.7
op = 100
By elbiie on Jul 10, 2009 | Reply
£70=70% or 0.7
divide through by the percentage to get the original price
£70/0.7 = £100