Answer:
3 months (12 weeks to be precise or 2.76164 months)
Explanation:
you save 20 dollars each week. You need 229.95. Divide that by how much money you make, you get the number of weeks.
229.95 / 20 = 11.4975.
You get the money at the end of the week (I presume) so you'll need another whole week, not just about half of it, to get the money you need, so you'll need 12 weeks, which is just about equal to 3 months.
Hope this helps