Question 111
In some junior high school, a group of students are asked to plant tulip bulbs. Each participating student will be required to plant at least one bulb. And students in the same grade will be planting the same number of bulbs. There are 6 possibilities for the number less than 100 of bulbs to be planted, and the smallest and the next smallest of these numbers are 52 and 64. What are the possible combinations for the numbers of 7th, 8th and 9th graders among the participating students.