The money he earned from an oil change is $20 x 5 =$ <<20*5=100>>100.
The money he earned from the repair is $30 x 10 = $<<30*10=300>>300.
The money he earned from the car wash is $15 x 5 = $<<15*5=75>>75.
Therefore, Cid earned a total of $100 + $300 + $75 = $<<100+300+75=475>>475.
#### 475