If a man spends an equal amount of money to buy three types of pens at $5$ Rs/pen,$10$ Rs/pen,and $20$ Rs/pen,what is the average cost per pen?

If the mean of the set of numbers ${x_1}, {x_2}, {x_3}, ..., {x_n}$ is $\bar x$,then the mean of the numbers ${x_i} + 2i$,$1 \le i \le n$ is

The mean of the values $\sin^2 10^{\circ}, \sin^2 20^{\circ}, \sin^2 30^{\circ}, \ldots, \sin^2 90^{\circ}$ is $........$

The mean of the series $a, a + nd, a + 2nd$ is

If a variable takes the discrete values $\alpha + 4, \alpha - \frac{7}{2}, \alpha - \frac{5}{2}, \alpha - 3, \alpha - 2, \alpha + \frac{1}{2}, \alpha - \frac{1}{2}, \alpha + 5$ where $\alpha > 0$,then the median of these values is:

The mean of the first three terms is $14$ and the mean of the next two terms is $18$. What is the mean of all five terms?