Answer:
She have both activities again on 20th day from now.
Explanation:
Given :Ronna has volleyball practice every 4 days
Ronna also has violin lessons every 10 days.
To Find : When will she have both activities again on the same day?
Solution:
We will find the LCM of 4 and 10
2 | 4 ,10
2 | 2 , 5
5 | 1 , 5
| 1 , 1
So,


Hence she have both activities again on 20th day from now.