1. Convert Time to Seconds:

* 3 minutes = 3 minutes * 60 seconds/minute = 180 seconds

* 4 minutes = 4 minutes * 60 seconds/minute = 240 seconds

2. Total Time:

* Total time = 180 seconds + 240 seconds = 420 seconds

3. Calculate Average Speed:

* Average speed = Total distance / Total time

* Average speed = 20 meters / 420 seconds

* Average speed = 0.0476 meters/second (approximately)

Therefore, the average speed of the object is approximately 0.0476 meters per second.