Question

Jenn recently took a road trip. She bought 15 gallons of gasoline for $1.68 per gallon and 12 gallons at a price of $1.76 per gallon. She filled her tank once on the way back with 16 gallons at $1.65 per gallon. What was the average fuel cost per gallon on Jenn’s trip?

Answer 1

Jenn bought 15 gallons of gasoline for $1.68 per gallon

12 gallons at a price of $1.76 per gallon

16 gallons at $1.65 per gallon

Total fuel cost is

$\begin{gathered} \text{Total cost of fuel}=(15\times1.68)+(12\times1.76)+(16\times1.65) \\ \text{Total cost of fuel}=25.2+21.12+26.4=\text{ \ 72.72} \end{gathered}$

Total number of gallons is

$\text{Total number of gallons}=15+12+16=43$

The formula to find the average fuel cost is

$\text{Average fuel cost}=\frac{Total\text{ fuel cost}}{Total\text{ number of gallons}}$

Substitute the values into the formula of the average fuel cost

$\begin{gathered} \text{Average fuel cost}=\frac{Total\text{ fuel cost}}{Total\text{ number of gallons}} \\ \text{Average fuel cost}=\frac{72.72}{43}=\text{ \ 1.69 (two decimal places)} \end{gathered}$

Hence, the average fuel cost is $1.69 (two decimal places)