Answer:
The right answer on edge is: I need to change my budget so that I save at least $300 per month. Over twelve months, this will increase my savings by $3,600. I also need to change my budget to save for a new computer, so I need to save an extra $100 a month for that. In total, I need to save $400 a month.
Explanation: I just did the test an got a 100