Alright well first off you start by converting everything to fractions, but decimals work better for me. So it would be 40.5 and 1.25, 40.5 being miles and the other gas. Divide 40.5 by 1.25, giving you 32.4
Let's call the side of square b x. Therefore, the side of square a is 0.5x, making its area 0.25x² and the area of square b is x². This means that the percentage is 25%.