Does the subject want to ask "One day 10 yuan's fixed investment fund can invest 3600 yuan a year"? According to relevant data, if the daily investment is 10 yuan, and there are 365 days in a year, the total annual fixed investment is 10 yuan/day ×365 days/year = 3,650 yuan/year. If you want to invest 3600 yuan at one time, you can choose to invest this amount at one time within one year, or invest 9.86 yuan every day within one year, so that the total investment can reach 3600 yuan a year.