Question 1187963
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