Answer:
30 houses
Step-by-step explanation:
Time from 6:30 pm to 8:45 pm = 2 hr 15 min
Time in minutes = (2 hr × 60 min/hr) + 15 min = 135 min
Average visit = 9 min per 2 houses = 4.5 min per house
Number of visits = 135 min ÷ 4.5 min/house = 30 houses