In order to find his beginning total we'll first add up how much he spent during the day
4.85 + 7.95 + 7.95 = 20.75
He spent $20.75 that day
He was left with $8.20 from what he originally had.
So, we'll add 20.75+8.20 = 28.95.
Sam had $28.95 to start with.