James’ mom checks up on the plants every so often to ensure that they won’t die. However, she’s going on vacation for the next 15 days. If James forgets to water the plants for 3 or more days the plants will die. Find the probability that James keeps the plants alive. Also, let Y be the random variable corresponding to the number of days James forgets to water the plant (Y ≤ 3) describe the PMF of Y.