(a)[1]
Draw pattern 5 above.
(b)[2]
Fill in the table.
(c)[1]
Find an expression, in terms of $n$, for the combined number of crosses and circles in pattern $n$.
(d)[1]
The expression, in terms of $n$, for the number of crosses in pattern $n$ is $\frac12n^2+\frac12n$. How many crosses are there in pattern $30$?
(e)[1]
Show that pattern $n$ contains $\frac12n^2-\frac12n$ circles.
(f)[3]
The number of crosses in pattern $m$ matches $5m$. Find $m$.