Answer:
Step-by-step explanation:
The variable t represents the amount of gas in mom's truck. Since we need to find a number that is 50% more than 12, we use 1.5 (we would use 2 if we want 100% more, so it makes sense that we use 1.5, since we want to add 1/2 of 12 to 12. The answer is 18.)