Question

Ravi can do a piece of work in 15 hours while Raman can do it in 12 hours. How long will both take to do it,working together?

Answer 1

Ravi do a piece of work in 15 hours.
Raman can do it in 12 hours.
Both working together will take = Ravi×Raman÷Ravi + Raman
= 15×12÷15+12
= 180÷27
= about 6.6 hours

Answer 2

Answer:

6.6 hours

Step-by-step explanation:

Ram can do work in 15 Hours.

He can do a part of work in 1 hour = $\frac{1}{15}$

Raman can do work in 12 Hours.

He can do a part of work in 1 hour = $\frac{1}{12}$

Together they can do work in 1 hour = $\frac{1}{12}+\frac{1}{15}$

                                                            = $\frac{9}{60}$

Together they can do 9/60 part of work in hour = 1

So, they can do 1 work in hours = $\frac{1}{\frac{9}{60}}$

                                                     = $\frac{60}{9}$

                                                     = $6.6$

Hence it will take 6.6 hours to complete the work if they will work together .