NZ Level 8 (NZC) Level 3 (NCEA) [In development]
Mixed problem

## Interactive practice questions

If you can choose one item from a group of $a$a items and a second item from a group of $b$b items, what is the total number of two-item choices?

Easy
Approx a minute

The number of possible permutations of $r$r objects taken from $n$n items is $\nPr{n}{r}$nPr. Express this in factorial form.

The number of possible combinations of $r$r objects taken from $n$n items is $\nCr{n}{r}$nCr. Express this in factorial form.

Evaluate $\frac{\nPr{8}{3}}{3!}-\nCr{8}{3}$8P33!8C3.

### Outcomes

#### M8-3

Use permutations and combinations