I am trying to help my brother with his exam preparations, and we came across this question and found the answer a little confusing. Here is the graph and the range, taken from the answers page of the practice questions.
Shouldn't the correct range be R\[0,10)?
Summarizing the contents of the comments so this question can be removed from the "unanswered" queue:
First of all, the book is wrong. The range of this graph is the entire real line except the region between $y=0$ and $y=10$. Since the function is defined at $y=0$ but not at $y=10$, the range should be $R\setminus(0,10]$ (or, more accurately, $\mathbb{R}\setminus(0,10]$).