I need help with this

7. Bill travels by boat 100 miles downstream the New River in 4 hours, helped by the current. On the trip upstream, it takes him 9 hours fighting the same current. At what rate of speed is the boat traveling (round your answers two decimal places)? 8. The Arcadian arcade in Lynchburg, Tennessee uses 3 different colored tokens for their game machines. For $20 you can purchase any of the following mixtures of tokens: 14 gold, 20 silver, and 24 bronze; OR, 20 gold, 15 silver, and 19 bronze; OR, 30 gold, 5 silver, and 13 bronze. What is the monetary value of each token