Question

The ratio of money in Obi's wallet to Rudy's wallet one day was 5:2. Obi spent £20 that day. Obi now had £8 less than Rudy. How much did Rudy initially have?

Answer 1

£8

Explanation:

If the ratio of money in Obi's wallet to Rudy's wallet one day was 5:2, then Obi had 5x and Rudy has 2x in their wallets.

Obi spent £20 and 5x-20 left. Obi now had £8 less than Rudy, thus,

`2x-(5x-20)=8,\\ \\2x-5x+20=8,\\ \\-3x=8-20,\\ \\-3x=-12,\\ \\x=4.`

This means that initially Obi had £20 and Rudy had £8.