Final answer:
The probability that a randomly selected student does not enjoy cake is 80%.
Step-by-step explanation:
To find the probability that a randomly selected student does not enjoy cake, we need to subtract the probability of enjoying cake from 1. We are given that 50% of the kids enjoy ice cream and 60% enjoy cake. However, 40% enjoy both types of foods. To find the percentage that only enjoy cake, we subtract the percentage that enjoy both from the percentage that enjoy cake: 60% - 40% = 20%. Therefore, the probability that a randomly selected student does not enjoy cake is 100% - 20% = 80%.