jmc

Let $x$ be the number of miles you ride. The number of miles you ride after the first half mile is $x-\mathrm{0.5.}$ We can write this equation: $$\begin{array}{rl}10& =2.4+0.2\times \frac{x-0.5}{0.1}+2\\ 5.6& =2(x-0.5)\\ 2.8& =x-0.5\\ x& =\boxed{3.3}\end{array}$$