Question

If in the expansion of$\frac{2}{5}$, the coefficient of x and $\frac{\sqrt{2}}{5}$are 3 and – 6 respectively, then m is.

• A. 6
• B. 9
• C. 12
• D. 24

Answer 1

Answer: (C)

12

Answer 2

$nC_{k}$

$nC_{n - k - 1}$

$99^{50} + 100^{50}$+.........

Given, m – n = 3 or n = m – 3

Hence $101^{50}$

⇒ $99^{50} + 100^{50}$

⇒ $101^{50}$

⇒ $(1 + x)^{n} - nx - 1$