Find the number of terms in the expansion of (a + b + c) n .

Question

Philoid · Accepted Answer

Given:

T_n = ;

Where p + q + r = n

Since number of ways in which we can divide n different things into r different things is : ^n+r-1C_r-1

Here, n=n & r=3

So, ^n+3-1C_3-1 = ⁿ⁺²C₂

so, the number of terms