If a discount of 20 percent off the retail price of a desk saves Mark 45 dollars how much did he pay for the desk?

Answer 1

Mark paid $180 for the desk.

Mark paid 100% - 20% = 80% of the original price. If 20% of the original price is $45, then, 80% being 4 times 20%, Mark's cost would be 4 times $45, or $180.

Call "price" the original, undiscounted price; call "cost" Mark's cost after the discount. Express percentages as fractions of 100. Then algebraically we can write two equations and then solve them together:

1: cost = (100-20)/100 X price; cost = 80/100 X price; cost = 0.8 X price

2: 20/100 X price = $45; $45 = 0.2 X price; price = $45/0.2; price = $225

Combining the first and second equations, we can write:

cost = 0.8 X price; cost = 0.8 x $225; cost = $180.

Here is the answer in more simple terms...lol: BY MR2K10

Let x= the original price of the desk

.20x= 45 (divide by .20)

___ ___

.20 .20

x=225

Now we know that Mark got $45 off the original price of the desk, therefore we subtract $45 from $225 which gives us $180. :)