Geometry please help!:(

What would be the cross section from a horizontal slice of the figure?

It would be triangle because you're cutting it

X and y are the times in hours that he travelled  on foot and on bus

x + y = 1.5   * by 5:-

5x + 5y  = 7.5
5x + 60y = 35    subtract:-

55y =  27.5
y = 0.5 
and x = 1.5 - 0.5 = 1

so he walked for 1 hour

distance he walked =  average speed * time =  5*1 = 5 miles.