Tara's parents gave her $90 for her birthday. Not wanting to spend it, Tara put the money in a new bank account that gains 10% interest annually. If she doesn't withdraw the money at all, how much will she have after a year? Let's think first. Chain of thought:
In one year, Tara's account will yield an interest of 10 / 100 * 90 = 9 dollars. The total in her account will therefore be 90 + 9 = 99 dollars.
Therefore, the answer is 99.