Question

If Romeo can do a job in 3 hrs. and Randy can finish the

same job in 6 hrs. How long would it take them to finish
the work?​

Answer 1

It would take them two hours to finish.

Explanation:

You can think of this in units of work per hour:

Romeo does 1w/3h

Randy does 1w/6h

so we simply need to add them together to find how much work per hour they can do:

`(1w)/(3h) + (1w)/(6h) \\= (2w)/(6h) + (1w)/(6h) \\= (3w)/(6h)\\= (1w)/(2h)`

So collectively, they can do one job in two hours.