A finch rides on the back of a Galapagos tortoise, which walks at the stately pace of

Question:

A finch rides on the back of a Galapagos tortoise, which walks at the stately pace of 0.060 m/s. After 1.5 minutes the finch tires of the tortoise's slow pace, and takes flight in the same direction for another 1.5 minutes at 11 m/s. What was the average speed of the finch for this 3.0-minute interval?