You can set up a ratio with 1/48 = 1/4 and 1 = x. You want to find a value that you can multiply the first equation by to get the second (called a scalar multiple). In our case, this is 48. So you multiple (1/48) * 48, and (1/4)* 48 to get an answer of (48/4), or 12 miles.
Since this is simple interest the equation will be P*T*R=I T=time which is 1 year. P=money invested or borrowed (aka princable) which is 400$. R=Annual rate is 3% per year and I= Interest after the number of years (aka answer) Hope this helps :)
