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)
Ruby negi
frequency is given, so find energy from here using E=h* frequency and then using uncertainty principle , you can find average life time i.e E.T=h/2π where E is energy and T is lifetime