Answer:
1 times
Explanation:
Hello,
The alumni have reunions every 10 years
But also have football games every 2 years
We have to find how often do the football and reunion fall the same year.
Working with a space of 10 years
In 10 years, reunions happen only once
In 10 years, soccer games happen five times
Assuming we're in the year 2020,
The next reunion would likely occur in year 2030.
But soccer games will happen in year 2022, 2024, 2026, 2028 and finally 2030.
Checking both soccer and reunion coincidence, we can only find one which is in year 2030.
So, soccer games and reunions happen once in 10 years