It will take 2 years.
Year 1 :
4% 2.5k = 2.5k/100 × 4 = $100 in interest
$2.5k + $0.1k = $2.6k
Year 2 :
4% 2.6k = 2.6k/100 × 4 = $104 in interest
$100 + $104 = $204 > $200
There may be a simpler way to solve this using a formula for example, but I just solved this step by step. Please feel free to ask if you have any questions
