Pooja is twice as efficient as Aarti and takes 90 days less than Aarti to complete the job. Find the time in which they can finish the job together.
Answer: C
Assume that Pooja completes the job in 'x' days.
So, Aarti will take '2x' days to complete the same job.
As Pooja takes 90 days less than Aarti, we get
x = 2x – 90
By solving this equation, we get x = 90 .
Thus, 2x = 2 x 90 = 180
Part of job done by Pooja in 1 day = 1/ 90
Part of job done by Aarti in 1 day = 1/180
(Part of job done together in 1 day) = (Part of job done by Pooja in 1 day) + (Part of job done by Aarti in 1 day)
= (1/90) + (1/180)
= 3/180
=1/60
(1/60)th part of whole job will be completed by Pooja and Aarti together in one day.
Therefore, the whole job will be completed in 60 days together.