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
here, I gice numbers to balls. and the desired figure is made by The balls 2,3,4,5..Nowsee, for contribution ,see like what I am saying, look balls interact only with neighboring balls, here ball 2 interact only with ball 3,1,5 so contribution of ball 2 is 1/3... similarly for ball 5(it ineract with ball 4,6,2).. Now for ball 3 , ball 3 interact with ball 6,2 ,only with two balls so contribution is 1/2 , similarly for ball 4.. therefore total contribution is 1/3+1/3+1/2+1/2 or u can write 2*1/3+2*1/2...