Use reasoning to lead to the answer of the following question:
Mark is reading books, for 2 hours each day. He decided to increase his time spent on reading books weekly, by 4 hours. How much time does Mark want to spend during one week on reading books?

18
Currently, Mark is reading books for 2 * 7 = 14 hours weekly.

His goal is to read books, for 14 + 4 = 18 hours during one week.

.

So, the answer is 18