Binomial Theorem
Finding $n$, $x$, $y$ from Consecutive Terms
nta_pyq_2024_apr
Grade 11
Question:
If the second, third and fourth terms in the expansion of $(x+y)^n$ are 135, 30 and $\dfrac{10}{3}$, respectively, then $6(n^3+x^2+y)$ is equal to _______.
Step-by-Step Solution
Key Concept: From ratios of consecutive terms: $x=9y$, $n=5$, $x=3$, $y=1/3$.
$n=5,x=3,y=1/3$. Answer $=806$.
Correct Answer: 806