Work/ Rate: By what percent is time taken...

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Work/ Rate: By what percent is time taken...

by euro » Mon Sep 27, 2010 12:17 pm
By what percent is the time taken by 12 men to complete a particular task, greater than the time taken by 10 women to complete the same task?

(1) The time taken by 6 men to complete a particular task is 25% more than the time taken by 5 women to complete the same task.

(2) The time taken by 10 men to complete a particular task is 10% less than the time taken by 6 women to complete the same task.

OA is [spoiler](D)[/spoiler]
Source: — Data Sufficiency |

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by clock60 » Mon Sep 27, 2010 1:23 pm
m-here the rate of 1 men, tm-time for men to complete the work,
w-the rate of one woman, tw-time for women to complete the work

12*m*tm=1 ( 12*rate*time) it is for men, tm=1/12*m
10*w*tw=1 it is for women. tw=1/10*w
and we need to know, what is (1/12*m)/(1/10*w)=((10*w)/(12*m)-1)*100, or simply what is w/m-?
(1) 6*m*time for men=1, time=1/6m it is for men
5*w*time for women=1. time=1/5w, and we are given that
1/6m=1,25*(1/5w) from here it is possible to find w/m-so suff

(2) 10*m*time=1 time=1/10m for men
6*w*time=1, time =1/6w, for women and we are given that
1/10m=(0,9)*(1/6w) from here it is also possible to calculate w/m suff
D for me also