Question

Let $(x + 10)^{50} + (x - 10)^{50} = a_0 + a_1 x + a_2x^2 + ..... + a_{50} \; x^{50} ,$ for all $x \in R ,$ the $\frac{a_2}{a_0}$ is equal to :-

• A. 12.5
• B. 12
• C. 12.75
• D. 12.25

Answer 1

Answer: (D)

12.25

Answer 2

$\left(10+x\right)^{50} +\left(10-x\right)^{50}$
$\Rightarrow a_{2} = 2. ^{50}C_{2} 10^{48} , a_{0} = 2.10^{50}$
$\frac{a_{2}}{a_{0}} = \frac{^{50}C_{2}}{10^{2}} = 12.25$