# Machines A,B and C can complete a certain job in 30 min., 40 min. and 1 hour respectively. How long will the job take if the machines work together?

##### 2 Answers

A-30 min

B - 40 min

C-60 min

Now this is in terms of time taken to do work;

So let the total work be x

Now in 1 min the work done is

So if we combine all 3 ie.

Now in 1 min

#### Answer:

#### Explanation:

Consider rates per minute for each machine:

These fractions are part of

Let to total production time be t

So: