Anne is a caring daughter. She visits her old parents after every 5 days. Tony her brother visits their parents after every 4 days. Each time the two siblings meet at their parent's house, they share a cake. On the 1st January they shared a cake at their parent's house. On what day and a month will Anne and Tony be sharing their next cake at their parent's house?

Question

GPT-4o mini · Answer

To find out when Anne and Tony will next meet at their parents' house after January 1st, we need to find the least common multiple (LCM) of the days they visit their parents.

Anne visits every 5 days, and Tony visits every 4 days.

To find the LCM:

The multiples of 5 are: 5, 10, 15, 20, 25, 30, 35, 40, ...
The multiples of 4 are: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, ...

The smallest common multiple in both lists is 20.

This means they will meet again after 20 days from January 1st.

Now we add 20 days to January 1st:

January has 31 days.
Adding 20 days gives us January 1 + 20 days = January 21.

Therefore, Anne and Tony will share their next cake at their parent's house on January 21st.