To differentiate between liters and milliliters, you can shift the decimal point three places to the right and fill in two zeros, or you can multiply 7.5 by 1,000 (since three zeros correspond to how many decimal places to move). Therefore, 7.5 liters of water equals 7,500 milliliters of water.
La proporción de ambas velas es 20/60, que simplificada es 1/3, por lo que debes tomar la cantidad de onzas que tiene la vela y dividirla por 1/3. Dicho de otra manera: 9 / 1/3 => 9 * 3 = 18
