Answer:
30 minutes
Explanation:
Max mow the lawn in minutes = 45
Max can mow a part of lawn in 1 minute =

We are given that Jan takes twice as long to mow the same lawn.
So, Jane took times to mow the lane =
minutes
Jane can mow a part of lawn in 1 minute =

Together they can mow the part of lawn in 1 minute =

=

So, they can mow
part of lawn in 1 minute
So, they can mow whole lawn in minutes=
=
=
Hence it will take 30 minutes to mow the lawn if they work together.