Sarika Z.

asked • 08/31/16

Work and rate

adults can do a job twice as fast as children. If X adults can complete a job in d days, how many children can do the same job in d+2 days? Answer in terms of d and X  

1 Expert Answer

By:

Mark M. answered • 08/31/16

Tutor
5.0 (278)

Mathematics Teacher - NCLB Highly Qualified

See tutors like this
See tutors like this
It takes 2X children to do the job in d days
2X : d :: c : d + 2           proportion      c represents number of children
cd = 2X(d + 2)               product  means/extremes
cd = 2Xd + 4X               distribute
c = 2X + 4X/d                divide both sides by d
 
Upvote • 0 Downvote
More
Report

Sarika Z.

But the answer is (2dx)/(d+2) 
I am very confused and I don't know how the book came to that conclusion 
Report

08/31/16

Mark M.

Without seeing the textbook, I cannot comment on the solution given.
I have checked mine and cannot see an error. Perhaps another tutor shall see one.
Report

08/31/16

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.