$LCM[2,3]=6$ 
Kate and Kerry are two dogs. Every $3$-hour, Kate goes to the dog park. Every $2$-hour, Kerry gos to the dog park. Today, Kate and Kerry first meet at $10:00\text{am}$. When will they meet each other again? 
A) $12:00\text{pm}$ 
B) $4:00\text{pm}$ 
C) $6:00\text{pm}$ 
D) $10:00\text{pm}$ 