Peter bought 4 1/ 2  ft of cable wire. The cable wire cost $1.80 a foot. How much did Peter pay for the cable wire? A student solved the problem this way. 41 2  feet =4.5  feet Let n represent the amount Peter paid for the cable wire. n=4.5×$1.80 n=$8.10  Peter paid $8.10 for the cable wire. Use a similar strategy to solve this problem. Bobby bought 35 12  ft of red ribbon and 51 12  ft of yellow ribbon. Ribbon costs $1.20 a foot. How much did Bobby spend on ribbon?