Answer:
exponential decay
Step-by-step explanation:
If the amount is 1/2 every half hour, it is getting smaller, so it is decreasing, leaving choices a and b
We start with 100 items
100, 50 ,25, 12.5
this is not linear so it must be exponential decay
exponential decay...................
what does the picture say?
Answer: The fourth one
20gallons
7.8