Cane sugar turns to dextrose. This is proportional to the amount of cane sugar yet to be converted. 100g of cane sugar is added and 12 g are converted into dextrose during the first hour. How much dextrose will be present in the juice after three hours?
$$\frac{dP}{dt}=kx\\\\P=pe^{kt}\\88=100e^{k(1)}\\k=-0.12783$$
Evaluating at t=3 gives an answer of 68.1472. The answer is supposed to be 31.85 and I have no idea where I am going wrong.
Am I messing up in the values I am using? Thanks in advance!