Alexander enjoys mountain biking. He has found that the maximum gradient which he can cycle up is 0.3, and the maximum gradient that he can safely descend is 0.5. His map has a
scale of 2 cm to 1 km, with contours every 25 m.
a. What is the minimum distance between the contours on his map that allows him to go uphill?
b. What is the minimum distance between the contours on his map that allows him to go
downhill?​