2. Equivalent units of labour and overheads and total cost per unit

The value of $\displaystyle N$ in $\displaystyle N! + \frac{1}{7!} = \frac{1}{8!}$ is

A person can go from place 'A' to 'B' by 11 different modes of transport but is allowed to return to 'A' by any mode other than the one earlier. The number of different ways in which the entire journey can be completed is:

If a man travels from place A to B in 10 ways then by how many ways can he come back by another train?

If $\displaystyle \frac{n!}{10(n-1)!} = \frac{(n-1)!}{(n-3)!}$ find 'n'.

Which of the following is a correct statement.

$\displaystyle ^nP_3 = 2 \cdot ^nP_2$. Find $\displaystyle n$.