Ruth filled her car with 21.2 gallons at the start of her trip. Upon arrival she recorded her odometer mileage of 43796 miles, but she realized she had forgotten to get her beginning mileage. Knowing that her car get an average of 21 mpg, what is the best estimate of her beginning mileage?

43,135 miles

Step-by-step explanation:

Given data

Average speed: 21 miles per gallon

Fuel: 21.2 gallons

The distance (d) traveled with this amount of fuel is:

21.2 gal * 21 mi/gal = 4,452 mi

The distance traveled is equal to the difference between the final reading of the odometer and the initial one.

d = final reading - initial reading

initial reading = final reading - d = 43,795 mi - 6.6 * 10² mi = 43,135 miles

We can estimate that the initial reading of the odometer was around 43,135 miles

Multiply 21•21.2 and then 437956-445 and you get 43,351