A, B and C do a piece of

Reilly Knox

Reilly Knox

Answered question

2022-03-15

A, B and C do a piece of work together. A could've done it in 6 hours longer, B in 15 hours longer and C in twice the time. How long did it take all three to do the work together?

Answer & Explanation

jednakoga5u

jednakoga5u

Beginner2022-03-16Added 3 answers

What is your reasoning for using the LCM? This is the part of your approach that does not make sense.
Convert the time it takes for each person to complete the job into a fraction of the job performed per unit of time (in this case, jobs per hour). That is to say, A has a work rate of 1x+6 of the job per hour; B works at a rate of 1x+15 of the job per hour; and C works at a rate of 12x of the job per hour. Therefore, when they all work together, their rate of progress is
1x+6+1x+15+12x
of the job per hour, and since it takes x hours for them to complete the job together, this means x times the above expression must equal 1 full job completed; i.e.,
x(1x+6+1x+15+12x)=1.

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?