My name is Paula Duncan
grade level of question grade 10-12,
I am assisting a student but am not a teacher.

My question is how would you calculate the following problem.

If it takes a typist 4.5 hours to type 860 words, how many hours would it take 6 typist to do 16800 words?

I would like to know how you would figure this question?

I am going to modify your problem slightly to make it easier, solve the modified problem and use the solution to see how to solve your problem.

If it takes a typist 4.5 hours to type 860 words, how many hours would it take 6 typist to do 17200 words?

Since 17200 is 20 times 860 it would take one typist 20x4.5 = 90 hours to type 17200 words. If this job is divided among 6 typists then they could do it in 90/6 = 15 hours.

If it takes a typist 4.5 hours to type 860 words, how many hours would it take 6 typist to do 16800 words?

Since 16800 is 16800/860 = 19.53 times 860 it would take one typist 19.53x4.5 = 87.91 hours to type 16800 words. If this job is divided among 6 typists then they could do it in 87.91/6 = 14.65 hours.