Solution :
Given, Tn = nC3
Tn+1 = n+1C3
∴ T_{n+1} – T_n = ^{n+1}C_3 – ^{n}C_3 = 10 [given]
\therefore ^nC_2 + ^nC_3 – ^nC_3 = 10
\implies ^nC_2 = 10
\therefore n = 5
Given, Tn = nC3
Tn+1 = n+1C3
∴ T_{n+1} – T_n = ^{n+1}C_3 – ^{n}C_3 = 10 [given]
\therefore ^nC_2 + ^nC_3 – ^nC_3 = 10
\implies ^nC_2 = 10
\therefore n = 5