SOLUTION: Hi, I need help with this word problem: A factory has an order for 23,500 paper clips. Machine A can make 1500 paper clips per hour while Machine B can make 2500 paper c

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Question 85254: Hi,

I need help with this word problem:

A factory has an order for 23,500 paper clips. Machine A can make 1500 paper clips per hour while Machine B can make 2500 paper clips per hour. Machine A starts at 8:00am and Machine B starts work at 1:00pm. At what time will the two machines complete the job?

Thank you!!!

Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!

When Machine B starts at 1:00pm, Machine A has already made 5*(1500) or 7500 paper clips. So when the two machines start working together at 1:00pm, there are 23,500-7500 or 16,000 paper clips yet to be made. Together, the machines can make 1500+2500 or 4000 paper clips per hour. So, in 16,000/4000 or 4 hours, they can finish the job and that would be 1:00pm plus 4 hours =5:00pm
Let x=amount of time it takes both machines to do the job after they both start working together at 1:00pm
So our equation to solve is:
1500*5+4000*x=27,500 or
7500+4000x=27,500 subtract 7500 from both sides
4000x=16000 divide both sides by 4000
x=4 hrs
1:00pm+ 4 hours =5:00pm
Hope this helps---ptaylor