If R(m) = 1600/(15m+2) then
R(0.1) = 1600/(15(0.1)+2) = 457.14 (approx)
In this case.
A curve banked with a slope of 0.1 feet should have a minimum radius of 457.14 feet.
Ans2) R(m) = 1600/(15m+2) and given R(m) =320 feet.
So,
320 = 1600/(15m+2)
m = 0.2
This curve will be banked with a slope of 0.2