You add 70 + 50 then you multiply it by 7.5 and you get, 900 gallons.
The points for C is (12, 10.5)
Because the ratio for both candles is 20/60 or 1/3 then take the number of ounces the candle has and divide by 1/3. In expression: 9 / 1/3 => 9 * 3 = 18
Here is the answer and steps. Answer:-3/5