There are 8 flapjacks in a batch, and each batch needs 4oz rolled
oats. Given 16oz of oats we can potentially make 16/4 = 4 batches,
provided we have enough of the other ingredients. 4 batches require
12oz sugar and 8oz butter, which we have, so we can make 4 batches,
which gives us 32 flapjacks.
This problem is taken from the UKMT Mathematical Challenges.