Question

Determine the no. of terms in the expansion of $(a+b+c+d{)}^5$ and $(1+a+a^2+a^3{)}^5$

• A. 56, 16
• B. 32, 24
• C. 165, 32
• D. 32, 32

Answer 1

The correct option is A 56, 16

No. of terms in expansion of $(a+b+c+d{)}^5$ = Number of solution of (a + b + c + d) = 5, ${}^8{C}_3$ = 56

No. of terms in expansion of $(1+a+a^2+a^3{)}^5=(5\times 3)+1=16$

Hence option (a)