There’s a formula for calculating the number of positive integral solutions.

a+b+c+ …n=m, then the number of positive integral solutions is m-1Cn-1. So in the question m=10 and n=3(only 3 terms a,b,c) 10-1C3-1=9C2=36

where did you learn this formula m-1cn-1

i should just memorize the formula

If the number i.e. m is small then we can actually list out all the values but then if the number is large, listing out all the values will be time-consuming.

Hey everyone, i got this one correct using a bit of logic but I think I am missing out one of the triplet. Can anyone please list out them? I am scratching my head for thirty minutes now.

There is no need to memorise. See GRE Medium Quant Practice - July 12, 2021, around the 56 minute mark, at New Content Feed - GregMat