Question
Question: If coefficient of a<sup>2</sup>b<sup>3</sup>c<sup>4</sup> in (a + b + c)<sup>m</sup>, (where mĪN) is...
If coefficient of a2b3c4 in (a + b + c)m, (where mĪN) is L (L ≠ 0) then in same expansion coefficient of a4b4c1 will be
A
L
B
3L
C
4mL
D
2L
Answer
2L
Explanation
Solution
as L ¹ 0 \ m = 2 + 3 + 4 = 9
\ L = 2!3!4!9!
Now coefficient of a4b4c = 4!4!1!9!=2L