If it moves 423 feet in 7 minutes, you divide 423 by 7 to see how much it moves per minute, which is Around 60.4 feet per minute
99.99 x (7%/100)= 6.9993
99.99+6.9993= 106.9893 (round up)
ANWSER- $106.99
Hope this helped.
You make them to improper fractions then you find a greatest common factor and then go from there