Vehicle 1 = 18 miles per gallon
Vehicle 2 = 16.67 miles per gallon
Vehicle 1
Based on the numbers we have we can assume that she saves 3 times more each week than the last (1*3=3, 3*3=9).
Following this trend we would multiply the amount she saved the third week ($9) by 3 to get $27 for the fourth week.
Then, we would multiply the amount she saved the fourth week ($27) by 3 to get $81 for the fifth week.
Finally, to figure out how much she saved in the 5 weeks, we need to add each value up to get 1+3+9+27+81= $121 saved in 5 weeks
