Final answer:
Neither Raúl M nor Oscar is correct; the ice cream truck and the food truck will next pass on the same day 56 days after their last joint appearance, which is neither one month nor two weeks from the time they passed together 15 days ago.
Step-by-step explanation:
To determine whether Raúl M or Oscar is correct about when the ice cream truck and the food truck will again pass on the same day, we need to calculate the least common multiple (LCM) of their visitation cycles. The ice cream truck passes every 8 days, and the food truck passes every 2 weeks (which is equivalent to 14 days).
First, we list the multiples of each cycle until we find a common multiple:
Multiples of 14: 14, 28, 42, 56, 70, ...
The smallest common multiple of 8 and 14 is 56. This means the two trucks will again pass on the same day every 56 days starting from the first day they both passed together. Since they last passed together 15 days ago, we add 56 to that number to find the next meeting day will be on the 71st day from their last meeting.
Therefore, neither Raúl M, who predicts one month later (30 or 31 days later), nor Oscar, who predicts two weeks later (14 days later), is correct. The trucks will meet again well after their predicted times.