Question

Count the possible combinations of r letters chosen from the given list P.Q,R,S,T,U; r = 2

Answer 1

There are 30 possible combinations of picking two letters.

Explanation:

The combinations are defined as

`C^(r)_(n)=(n!)/((n-r)!)`

Where
`n` is the total number of elements and
`r` is the number of letter we are gonna picke, which is two. Using this information, we have

`C^(2)_(6)=(6!)/((6-2)!)=(6!)/(4!)=(6 * 5 * 4!)/(4!)=30`

Therefore, there are 30 possible combinations of picking two letters.