JEE PYQ: Binomial Theorem Question 7
Question 7 - 2021 (17 Mar Shift 2)
Let the coefficients of third, fourth and fifth terms in the expansion of $\left(x + \frac{a}{x^2}\right)^n$, $x \neq 0$, be in the ratio $12:8:3$. Then the term independent of $x$ in the expansion is equal to ____.
Show Answer
Answer: 4
Solution
After solving, $n = 6$, $a = 1/2$. Term independent of $x$: $r = 2$, coefficient is ${}^6C_2(1/2)^2 = 15/4$. Nearest integer is 4.
BETA
