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

Answer:

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#