Algebra

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Algebra

by Deepthi Subbu » Sat Nov 13, 2010 3:17 am
Pat , Kate and Mark charged a total of 162 hours to a certyain project . 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?
1. 18
2.36
3.72
4.90
5.108

OA is D
Last edited by Deepthi Subbu on Sat Nov 13, 2010 4:10 am, edited 1 time in total.
Source: — Problem Solving |

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by beat_gmat_09 » Sat Nov 13, 2010 3:32 am
Deepthi Subbu wrote:Pat , Kate and Mark charged a total of 162 hours to a certyain project . 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?
1. 18
2.36
3.72
4.90
5.108
P=2k=1/3M
M=6K.
M-K = 5K = ?
2K+6K+K = 162, K=18.
M-K=5*18 = 90.
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by Deepthi Subbu » Sat Nov 13, 2010 4:14 am
Thats a simple method!

But this is how I proceeded

P + 2P + 3P = 162

6 p = 162 , p - > 27

hence kate - 54 and mark - > 81

So M - K -> 27

Where am I wrong?

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by beat_gmat_09 » Sat Nov 13, 2010 9:03 am
Deepthi Subbu wrote:Thats a simple method!

But this is how I proceeded

P + 2P + 3P = 162

6 p = 162 , p - > 27

hence kate - 54 and mark - > 81

So M - K -> 27

Where am I wrong?
P + K + M = 162.
P = 2K = (1/3) M
K = 1/2*P
M = 3P
You substituted the wrong value of K, K=1/2*P and not 2P, you substituted M correctly.
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by Deepthi Subbu » Sat Nov 13, 2010 10:55 am
Oops,ya . Thanks