The oak tree in the main square in Mathsborough is 432 years older than the town hall.
36 years ago it was 17 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
$$t = 432 + h$$
$$(t-36) = 17 (h-36)$$
$$\Rightarrow h + 396 = 17 (h-36)$$
$$h+396 = 17 h - 612$$
$$1008 = 16 h$$
$$h = 63$$
$$\Rightarrow t = 495$$
Therefore the town hall is 63 years old and the oak tree is 495 years old.