A student at a university makes money by buying and selling used cars. Charles bought a used car and later sold it for a 15% profit. If he sold it for $4623, how much did Charles pay for the car?

So to answer this problem you would need to set up an equation as the original price and the 15% percent of the original price is unknown. If x is the original price then x + 15% of the original price will equal 4623.

x +.15x=4623

Combine the like terms

1.15x=4623

Solve

x=4020