Joshua sold his bike for 10% less than he paid for it. lf he sold the bike for $585, how much did he pay for it?

1 Answer
Nov 16, 2016

Joshua originally paid $650 for the bike.

Explanation:

The formula for determine percent change is: p = (N - O)/O * 100 where p is the percent change, N is the new price, O is the old price. In this problem p and N are provided so we can substitute for these and solve for O while keeping the equation balanced:

-10 = (585 - O)/O * 100

-10/100 = (585 - O)/O * 100/100

-0.1 = (585 - O)/O

-0.1 = 585/O - (O)/O

-0.1 = 585/O - 1

-0.1 + 1 = 585/O - 1 + 1

0.9 = 585/O

(O)/0.9 0.9 = 585/O (O)/0.9

O = 585/0.9

O = 650