The central texas drought causes water level of area lakes to exponentially decay by a rate of 20% per year. if lake travis had 300 billion gallons of water in 2010, how many billions of gallons are left in three years

In all honesty, there really is no “work” per say to show. mainly it’s just using the process of elimination. the question is asking which domain(s) would be the most appropriate for the function c(n). n is the number of observed vehicles so right away, 1, 2, and 3 can be eliminated.why? 1, 2 start in the negatives and therefore it is impossible to observe negative cars. so, #4 would be the best answer to the given problem.

Ithink the answer is: it is likely.