Question

Which of the following must hold good for the expansion of the binomial x⁴ + 1/x³)¹⁵ ?

(A) There exist a term which is independent of x.

(B) 8 ^th and 9 ^th terms of the expansion have the greatest binomial coefficient

(C) Coefficients of x ³² and x ^-17 are equal

(D) If x =  √2 , then number of rational terms in the expansion is 5

Answer 1

Correct option (B)(C)

Explanation:

(A) for the term independent of x, 60 - 7r = 0 

⇒ r is not an integer 

∴ there is no term independent of x.

(B) ∴ n = 15 is odd

∴ for rational terms r = 0, 2, 4, 6, ....... 14