SOLUTION: machine A can do a piece of work in 6 hours , machine B can do the same work in 9 hours. machine A was set to do the piece of work but, after 3 and a half hours, it broke down and

Question 1149844: machine A can do a piece of work in 6 hours , machine B can do the same work in 9 hours. machine A was set to do the piece of work but, after 3 and a half hours, it broke down and machine B did the rest of the work. find how long the machine B took to do the rest of the work?
Answer by ikleyn(52750) (Show Source): You can put this solution on YOUR website!
.


Machine A worked 3.5 hours, then it was broken.


In 3.5 hours, machine A completed   =  of the whole work;

so,    remained to do.


Machine B has rate of work    of the job per hour;

so machine B will complete the remaining work in   =  =  hours =  hours =  hours = 3 hours and 45 minutes.   ANSWER

Solved.

---------------

It is a standard and typical joint work problem.

There is a wide variety of similar solved joint-work problems with detailed explanations in this site. See the lessons
    - Using Fractions to solve word problems on joint work
    - Solving more complicated word problems on joint work
    - Selected joint-work word problems from the archive

Read them and get be trained in solving joint-work problems.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic
"Rate of work and joint work problems" of the section "Word problems".

Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.

RELATED QUESTIONS
Please help me solve this question: Machine A can do a piece of work in 6hrs while... (answered by Theo)

Machine A can do a job alone in 10 hours. Machine B can do the same job alone in 12... (answered by Boreal,ikleyn,math_tutor2020)

Please solve me this question. "machine a can do a job in 10 hours. machine B takes 6... (answered by ikleyn)

An old machine can do a certain unit of work in 12 hours. To increase production, a more... (answered by josmiceli)

printing machine A can do printing in 8 hours. With the machine B the same printing would (answered by josgarithmetic)

A company has a machine that can complete a job in 6 hours. With the help of a newer... (answered by checkley77)

A new automatic machine can do a job in 1 hour less than an older machine. Together they... (answered by TimothyLamb)

Machine A can do a certain job in 8 hours. machine B can do the same job in 10 hours.... (answered by stanbon)

Kong can do a piece of work in 8 hours, (answered by richwmiller)