nevermind.

Question

disregard this.

Answer 1

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

Answer 2

If R(m)=1600/(15m+2):

Q1. R(0.1)=1600/(1.5+2)=1600/3.5=457.1ft.

Q2. 320=1600/(15m+2), 15m+2=1600/320=5, m=3/15=1/5=0.2ft.