I don't think that anybody in Elementary School would Understand this you might want to post this question in the High School section.
Hope it gets answered :)
I believe that the number of miles traveled would be 8. This is because you would subtract $5.00 from the $13.80 and then divided by $1.10.
This refers to the "denominator" of a fraction. By definition, the denominator tells you how many you need to have of an equal part in order to create a whole. The numerator tells you how much of those equal parts you have.
we are given
there are in 0.073 gallons
we can see that there are two non-zero places after decimals
so, there are two siginificant figures
step-1: Change gallons to quarts
we know that
1 gallon = 4 quarts
so, we can write as



step-2: Change into liter

we know that
1 liter = 1.057 quarts
or




step-3: Change into millilitre
we know that



Since, it is asking for only two significant figures
so, we can also write as

...................Answer
Add up the sum and divide.
Practice Chart
1st Week: 6.25 Hours
2nd Week: 4.66 Hours
3rd Week: 15.33 - (1st Week + 2nd Week)
Solve:
6 1/4 + 4 2/3 = 10 8/12 or 10 2/3
15 1/3 - 10 2/3
14 4/3 - 10 2/3
4 2/3 hours practiced third week
Hope this helps!