A classroom has

$3$

$0$

$$numbered seats arranged in six rows and five columns as shown For any given seat

$$

$$

$,$

$$come up with: b

$)$

$$An expression

$$

$$

$($

$$

$$

$)$

$$that calculates the corresponding column number.

Test your expressions by calculating

$$

$$

$($

$$

$$

$)$

$$and

$$

$$

$($

$$

$$

$)$

$$for

$$

$$

$$ in

$\{$

$1$

$,$

$4$

$,$

$5$

$,$

$1$

$4$

$,$

$2$

$5$

$,$

$2$

$6$

$\}$

$.$