The oak tree in the main square in Mathsborough is 68 years older than the town hall.
16 years ago it was 5 times older than the town hall.
Write these statements as equations and hence work out the age of the town hall and oak tree.
Let $t$ be the age of the tree and $h$ be the age of the hall. Then we have
$$t = 68 + h$$
$$(t-16) = 5 (h-16)$$
$$\Rightarrow h + 52 = 5 (h-16)$$
$$h+52 = 5 h - 80$$
$$132 = 4 h$$
$$h = 33$$
$$\Rightarrow t = 101$$
Therefore the town hall is 33 years old and the oak tree is 101 years old.