Answer: 4 years
Explanation:
Your question isn't complete but I believe that you want to calculate the number of years. This will be:
Simple Interest = PRT/100
where,
Interest = 864 - 800 = 64
Principal = 800
Rate = 2%
Therefore, 64 = 800 × 2 × T /100
Cross multiply
64 × 100 = 1600T
6400 = 1600T
T = 6400/1600
T = 4
Therefore, time will be 4 years