GMATprep Quantative discuss

r59208

Pat,Kate , and Mark charged a total of 162 hours to a certain project. if Pat charged twice as much time to the project as Kate and 1/3 as much time as Mark, how many more hours did Mark chaged to the project than Kate?

Answer is: 90hours

WHY?WHY?WHY?

My result is 1350 hours

athen

已知P+k+M=162 (1)
P=2K=M/3 (2)
问M-k=?

根据（2）， M=6K

因此 2K+6K+k=162

k=162/9=18

M-k=5k=90

r59208

对了！多谢！

我先前的理解是三个人一起合做会用162小时