Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Priyadarshan Choursiya
I think you have only problem to changing the order. so I only solve the order, then try to solve integral by yourself.