Answer:
22 hours and 30 minutes
Explanation:
I converted the time for 3 dogs into minutes. Then divided the 90 minutes by 3. Which meant one dog takes 30 minutes per walk. With that I multiplied 30 minutes by 45 (dogs) which gave me to total 1350. Which is in minutes so I converted that to hours by dividing it by 60. Which gave me 22.5 or 22 and a half hours