Final answer:
After subtracting the cost of the gas can from the total spent, Luiza's expenditure on gas was $14.00. Dividing this by the cost per gallon ($3.50), we find that she purchased 4 gallons of gas.
Step-by-step explanation:
To determine how many gallons of gas Luiza put in the can, we need to subtract the cost of the gas can from the total amount spent and then divide by the price per gallon of gas.
The gas can cost $18.50, so subtracting that from the total spent, $32.50, gives us the amount spent on gas alone: $32.50 - $18.50 = $14.00.
If gas costs $3.50 per gallon, we then divide the amount spent on gas by the cost per gallon: $14.00 ÷ $3.50 = 4 gallons.
Therefore, Luiza put 4 gallons of gas in the can. The correct answer is b) 4 gallons.