BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Algebra

Expert replies
by phoenix9801 » Sun Jun 27, 2010 12:47 am
Hi, can someone please help to explain the step-by-step instructions (in detail) in the most simplest way and clear to understand.


1-
A Part-time employee whose hourly wage was uncreased by 25 percent decided to reduce the number of hours worked per week so that the employee's total weekly income would remain unchanged. By What percent should the number of hours worked be reduced?
Join the discussion
Source: — Problem Solving |

by albatross86 » Sun Jun 27, 2010 12:59 am
Original hourly wage: X New hourly wage 1.25X

Original number of hours: Y New number of hours: Y - Z (where Z is the number of hours reduced)

Original weekly income: X*Y
New weekly income: 1.25*X*(Y-Z)

Equate the two:

X*Y = 1.25*X*(Y-Z)
=> Y = 1.25*Y - 1.25*Z
=> 0.25*Y = 1.25*Z
=> Z = 0.25/1.25 * Y = Y / 5

So Z is 20% of Y, which means we have to reduce Y by 20% to get the same weekly income.
Join the discussion