Carcass wrote:
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 charge to the project than Kate?
A. 18
B. 36
C. 72
D. 90
E. 108
\(P = 2K\)
\(\frac{P}{K} = \frac{2}{1}\)
\(P = \frac{1}{3}M\)
\(\frac{P}{M} = \frac{1}{3}\)
Let's make \(P\)s equal;
\(\frac{P}{K} = \frac{2}{1}\), \(\frac{P}{M} = \frac{1(2)}{3(2)}\)
Therefore, \(P : K : M = 2 : 1 : 6\)
Now, \(M - K = \frac{(6 - 1)}{(2 + 1 + 6)}(162) = \frac{5}{9}(162) = 90\)
Hence, option D