SOLUTION: A garrison of 1200 men is provisioned for 15 weeks.How many weeks can the same provisions last if 200 men left after 5 weeks?

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Question 975772: A garrison of 1200 men is provisioned for 15 weeks.How many weeks can the same provisions last if 200 men left after 5 weeks?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Think of this as uniform rates, task completion or doing a job. The agents doing the task of consuming provisions are the "men".

r, the consumption rate of 1 man. Time unit is "weeks". Unclear how to take the quantity and unit for the provisions being consumed

1200r%2A15 would be the given described provisions for the 1200 men for 15 weeks.

The question uses two different quantities of men and time, but for the same quantity of provisions. Something%2BsomethingElse=1200r%2A15. Those two terms or parts are these:

highlight_green%281200r%2A5%2B%281200-200%29r%2At=1200r%2A15%29, and the new variable, t, is included for the time asked in the question. If this equation makes sense to you, then solving and understanding the result should be no difficulty for you.

1200%2A5%2B1000%2At=1200%2A15
1000t=1200%2A15-1200%2A5
10t=12%2A15-12%2A5
10t=120
highlight%28t=12%29