Question

$\left( y^{2} + \frac{c}{y} \right)^{5}$

• A. n
• B. 1/n
• C. $20c$
• D. $10c$

Answer 1

Answer: (C)

$20c$

Answer 2

Sol. Trick : Put $\frac{2^{n + 1} - 1}{n + 1}$ 1, 2

At $\frac{1}{1!(n - 1)!} + \frac{1}{3!(n - 3)!} + \frac{1}{5!(n - 5)!} + .... =$

At $\frac{2^{n}}{n!}$

which is given by option (3).