Rylee is bored and decides to count the number of leaves falling off the tree in her backyard. 7 leaves fall in the first hour. For the second and third hour, the leaves fall at a rate of 4 per hour. What is the average number of leaves which fell per hour? Let's answer step by step:
7 leaves fell in the first hour. 4 leaves fell in the second hour. 4 leaves fell in the third hour. The total number of leaves that fell during the 3 hours is 7 + 4 + 4 = 15 leaves. The average number of leaves that fell per hour is 15 leaves / 3 hours = 5 leaves per hour. The answer: 5.