Answer:
25 and 31, respectively
Explanation:
1. Divide the number of miles (77 1/2) by the number of gallons (3 1/10).
2. Whatever number you get is where you place your dot
Tip: Converting fractions to decimals can make the work easier (in this case [77 1/2=77.5], [3 1/10=3.1], [99 1/5=99.2], and [3 1/5=3.2]