Rony spent 20% of his salary on a wallet. He bought a bag which cost $20 more than the wallet. He also bought a pair of shoes. The ratio of the cost of the wallet to the cost of the pair of shoes was 5:6. He then had $844 left.

(a) What was his monthly salary?
(b) Express the amount of money he spent on the pair of shoes as a fraction of his monthly salary in its simplest form.