First let's find how many kilometers the jeep traveled, by subtracting the odometer readings:
[tex]23684-23408.1=275.9[/tex]Now, to find the miles per gallon, we just need to divide the kilometers by the amount of gallons of gasoline:
[tex]\frac{275.9}{15.5}=17.8[/tex]So Harry got 17.8 miles per gallon with the Jeep.