Simple Rate, Time Math question

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Simple Rate, Time Math question

by iwillsurvive101 » Sun May 13, 2012 2:23 pm
Ref: OG12 Problem 154

Simplified form of the quetion. If Rate = 3/40 and Work = 2/5. What T(Time?) = ?

3/40 t = 2/5
=> t = 2 X 40 / (5* 3)

t = 16/3

Now if I divide 16/3, I get t = 5.33.

I picked 5.3 hours, but the correct answer is 5.2 hours. How is that possible?

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by Bill@VeritasPrep » Sun May 13, 2012 4:02 pm
1/3 of an hour is 20 minutes, and the correct answer is 5 hrs 20 min.

5.2 hours would be 5 hrs 12 min.
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by Anurag@Gurome » Sun May 13, 2012 9:16 pm
iwillsurvive101 wrote:Ref: OG12 Problem 154

Simplified form of the quetion. If Rate = 3/40 and Work = 2/5. What T(Time?) = ?

3/40 t = 2/5
=> t = 2 X 40 / (5* 3)

t = 16/3

Now if I divide 16/3, I get t = 5.33.

I picked 5.3 hours, but the correct answer is 5.2 hours. How is that possible?
Work = Rate * time
Let time = t
2/5 = (3t/40)
t = 16/3 = 5 1/3 (this is a mixed fraction)
5 (1/3 * 60) = 5 hrs 20 minutes is the correct answer.
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