Tia was flying her model airplane. It took the airplane 5 seconds to go 90 feet. What was the average rate of speed of the model airplane, in feet per second?

90 90/5 = ______ feet per second

To find the average rate of speed of Tia's model airplane, you need to divide the total distance covered by the time taken. In this case, the distance covered by the airplane is 90 feet, and the time taken is 5 seconds.

To calculate the average rate of speed, you can use the formula: average speed = distance / time.

Plugging in the given values, the average speed of Tia's model airplane can be calculated as follows:

average speed = 90 feet / 5 seconds
average speed = 18 feet/second

So, the average rate of speed of Tia's model airplane is 18 feet per second.