work rate

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work rate

by jainrahul1985 » Sun Jul 26, 2009 9:16 am
Working together, John and Jack can type 20 pages in one hour. They will be able to type 22 pages in one hour if Jack increases his typing speed by 25%. What is the ratio of Jack's normal typing speed to that of John?
1/3
2/5
1/2
2/3
3/5
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by ymach3 » Sun Jul 26, 2009 3:40 pm
(Rja + Rjo) * 1 = 20

(1.25Rja + Rjo)=22

On Solving both equations, we get Rja/Rjo = 2/3


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Re: work rate

by mehravikas » Mon Jul 27, 2009 9:21 pm
Another way to solve this would be -

Lets assume Jack's normal speed to be J, therefore .25J = 2

Jack's normal speed = 8 pages per hour
John's would be 12

Ratio = 2/3
jainrahul1985 wrote:Working together, John and Jack can type 20 pages in one hour. They will be able to type 22 pages in one hour if Jack increases his typing speed by 25%. What is the ratio of Jack's normal typing speed to that of John?
1/3
2/5
1/2
2/3
3/5