Students to participate in rope skipping competition according to a group of 4 or 8 or 10, group, just finished, to participate in rope skipping at least how many students?

Students to participate in rope skipping competition according to a group of 4 or 8 or 10, group, just finished, to participate in rope skipping at least how many students?

4. The least common multiple of 8 and 10 is 40