Answer:
15%
Explanation:
As we see, by the time one day passes, we have the amount of weeds as 1650 times 0.85 to the power of 1. We can rewrite 0.85 as 85%. That means that 1650 keeps getting multiplied by 85% to the power of as many days that have passed. 85% can be rewritten again to 1 - 15%. We can see in the equation that the population of weeds decreases by 15% as d, increases, and d is the number of days, so the population of the weeds decreases by 15% each day.