Will and Christine will work together to proofread a 420-page manuscript. Will takes 4 minutes to proofread one page and Christine takes 3 minutes to proofread one page. If each proofreader, at maximum, can proofread for 18 hours, what is the fewest number of hours that Will will have to spend proofreading this manuscript?
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Took me a second to realize we're minimizing Will's time, not splitting work evenly. Key is Christine works as much as she can first.
Exactly, that flipped it for me too. The phrase 'fewest number of hours that Will' is the whole game here.
Same. I initially set up a 50/50 split and got a weird answer that wasn't even a choice.
Is Christine's max 18 hours = 1080 minutes? Just want to make sure I'm converting right before I figure out how many pages she covers.
Yep, 18*60 = 1080 min. Then divide by her per-page rate to get her page count.
This one is trickier than it looks. The rate difference between 4 and 3 min/page matters a lot when you're trying to push one person to the limit.
Agreed, it's a 605-655 for a reason. Easy to overlook that we should max out the faster reader.
Got it after realizing total pages is 420 and the leftover pages after Christine maxes out must fall to Will. Solid work-rate question.
What it tests
Your ability to combine individual work rates, usually by working with the fraction of a job completed per unit of time.
Common trap
Adding the times instead of the rates, or forgetting to take the reciprocal when combining rates.