The question goes like this:
A shopkeeper wants to check is profits from selling sweet drinks. His business model is to multiply his stock of sweet drinks each month, and every day he sell exactly 15 drinks. Assuming each drink costs 5 dollars and in the first day he had 1000 drinks in his stock. What are his profits after 3 months? (assuming a month has 30 days)
There is a hint: first, find how many drinks are in his stock after 30 days.
To solve it I need to convert this problem into a differential equation.
I started by declaring y(t) the numbers of drinks in his stock after t months. With y(0)=1000.
However I am not sure what is the right ODE here. I am thinking y'=$2*(y(t)-30*15)$ but I'm not sure.
So I need some help.
Solving the equation though should be really simple.