Answer:
It will take 16 days.
Explanation:
50-18=32
32/2=16
32 represents the total amount of money spent before ending up with $18 left. If you spend $2 a day, just divide 32/2 (Total/Rate?). The final answer is 16 days.
To check, divide 50/2 to get 25 (days) and subtract the days we have (16).
25-16=9
9x2=18 or the $18 in the end of the problem.
If any of that was confusing, I'll be happy to answer any questions. It's just a pretty easy question so I am not sure if I did anything how you want or don't want it done.