Pat, Kate and Mark charged :: Manhattan GMAT Forums

Posted: Mon Apr 28, 2008 8:16 am

Pat, Kate and Mark charged a total of 162 hours to a certain project. If Pat charged twice as much to the project as Kate and 1/3 as much time as Mark, how many more hours did Mark charge to the project than Kate?
A. 18
B. 36
C. 72
D. 90 - correct
E. 108

Please help. Thanks.

Posted: Mon Apr 28, 2008 1:43 pm

got it!

6x+2x+x = 9x = 162. solve for x. Mark has 108 and Kate has 18 so the difference is 90.

pls feel free to ignore!

Posted: Thu May 15, 2008 5:46 pm

Glad it worked out.

Posted: Sat Sep 27, 2008 12:56 pm

Rey, could you please explain, how the guest got the above equation. thanks

Posted: Tue Oct 14, 2008 3:47 am

Capthan wrote:

Rey, could you please explain, how the guest got the above equation. thanks

step 1 * recognize that everyone's hours are connected to everyone else's hours, and that therefore only one variable is necessary in this problem

step 2 * use the variable for kate, because kate works the smallest number of hours (thereby avoiding fractions)

step 3 *
kate = x
pat = 2(kate) = 2x
mark = 3(pat) = 6x

step 4 *
kate + pat + mark = 162
x + 2x + 6x = 162