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Question 1187963: Hello
I'm stumped on how to workout this question. Could you please tell me how I go about solving it?
Two Carpenters are building each a small dog house. Carpenter A started building his at 1 pm and ended at 5:30 pm. Carpenter B, being a newbie is more slower than A by half. At what time must Carpenter B start building so that he can end at the same time
with A
Thanks in Advance.
Found 2 solutions by ankor@dixie-net.com, Theo:
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Two Carpenters are building each a small dog house.
Carpenter A started building his at 1 pm and ended at 5:30 pm.
A works for 4.5 hrs to complete his house
:
Carpenter B, being a newbie is more slower than A by half.
Therefore B had to work 9 hrs to complete his house
:
At what time must Carpenter B start building so that he can end at the same time
with A
A finished at 5:30 so B had to start 9 hrs before that to complete at the same time>
Using the 24 hr clock, 5:30 Pm is 17:30. 17:30 - 9:00 = 8:30 Am, B must start
Answer by Theo(13342)  (Show Source):
You can put this solution on YOUR website! carpenter A starts at 1:00 pm and finishes at 5:30 pm.
that means it takes carpenter A 4 hours and 30 minutes to finish the job.
that's equivalent to 4.5 hours.
carpenter B works slower than carpenter A by half.
i think that means:
if carpenter A takes 4.5 hours to complete the job, then carpenter B would take 4.5 hours, plus half of that = 2.25 hours, for a total of 6.75 hours.
assuming that's what it means, then, if carpenter B wants to finish the job at the same time as carpenter B, he would have to start his job 2.25 hours before carpenter B.
2.25 hours is equal to 2 hours and .25 * 60 = 15 minutes.
if carpenter A started at 1:00 pm, then carpenter B would have to start 2 hours before that = 11:00 am plus another 15 minutes before that = 10:45 am.
to see if that makes sense, then:
carpenter A starts at 1:00 pm and works for 4 hours and 30 minutes to complete at 5:30 pm.
carpenter B starts at 10:45 am and works for 6 hours and 45 minutes to complete at 5:30 pm.
they both complete at the same time.
to do the arithmetic, it helps to convert everything to hours, do the arithmetic, and then convert back to hours and minutes.
under that assumption:
5:30 pm is equal to 5.5 pm.
1:00 pm is equal to 1 pm.
subtract 1 from 5.5 to get 4.5 hours.
5:30 pm is equal to 5.5 pm.
10:45 am is equal to 10.75 am.
convert everything to 24 hours clock and:
5.5 pm is equal to 17.5 on the 24 hour clock.
10.75 am is equal to 10.75 on the 24 hour clock.
17.5 minus 10.75 = 6.75 hours.
6.75 hours is longer than 4.5 hours by half, assuming that meaning is correct for the expression.
your solution is that carpenter B would have to start at 10:45 am so that he can finish at the same time as carpenter A.
let me know if you have any questions.
theo
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