SOLUTION: A project must be finished in 80 days. Contractor A costs $ 150 a day; Contractor B costs $ 100 per day. The project manager has three possible choices: (a) Hire contractor A al

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A project must be finished in 80 days. Contractor A costs $ 150 a day; Contractor B costs $ 100 per day. The project manager has three possible choices: (a) Hire contractor A al      Log On


   

Question 358532: A project must be finished in 80 days. Contractor A costs $ 150 a day; Contractor B costs $ 100 per day. The project manager has three possible choices:
(a) Hire contractor A alone. The project would be finished just in time.
(b) Hire contractor B alone. But it’d take 100 days.
(c) Mix use of contractor A and contractor B.
Find the solution to minimize total cost and to meet deadline
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

Note: contractor A will cost $12,000 working alone to finish in 80 days

Finding the time it would take working together.



%281%2F80%29+%2B+%281%2F100%29+=+%281%2Fx%29

Multiplying thru with 80*100*x to clear the denominators

100x + 80x = 8000

180x = 8000

x = 44.44 hrs   Time would meet deadline..

Cost:

150*44.44hr + 100*44.44hr = 6666.66 + 4444.44 = $11,111.17

Mix use of contractor A and contractor B would minimize the total cost (and meets deadline)