Meghana alone would take 32 hours more to complete a job than both Meghana and Ganesh together. If Ganesh worked alone, he took 12 1/2 hours more to complete it than both Meghana and Ganesh worked together. What time would they take if both Meghana and Ganesh worked together?

Time taken by both Meghana and Ganesh to work together is given by =

$t1 x t2$

Where

$t1 = 32 hrst2 = 12 \frac{1}{2} hrs = \frac{25}{2} hrs$

Therefore, time took by both to work together = 

$32 x \frac{25}{2} = 16 x 25 = 4 x 5 = 20 hrs$