Answer: 5 bundles are needed
Step-by-step explanation: Say that the length of the bundles are 10 Then the amount needed for park 2 would be 10pi. Then you would need 5pi for park 1. Then 15pi would be needed for park 3, and 20pi would be needed for park 4. Adding it all up, it would be 50pi. Dividing 50pi by the original bundle length 10pi, we get 5 as our length.