The answer is 20. I hope this helps.
Slope of function B is "rising" 3 and going over to the right by 1. Representing the slope as 3/1 = 3.
Slope of function A is already giving. If you multiply the slope of function B by 2, it will equal the slope of Function A
Set up equal ratios
t/6=0.75/4.5 multiply both sides by 6
t=4.5/4.5
t=1 hour
So it will take Madison one hour to ride another six miles.
The answer in simplest form would be 2 and 3 fifths gallons of gas.