Answer:
72 houses.
Step-by-step explanation:
We are told that a postal worker can deliver the mail to 18 houses in 15 minutes.
Let us find numbers of mails delivered by postal worker per minute.
Since we know that 1 hour equals 60 minutes, so we will multiply 1.2 by 60 to find the number mails postal worker will deliver in 1 hour.
Therefore, the postal worker will be able to deliver mails to 72 houses in 1 hour.