Answer: $136.50
Step-by-step explanation: We have 26 boards, each 3.5 feet long. That means we have to multiply the 26 boards by 3.5 in order to find how many feet of boards there are. 26 • 3.5 = 91 so we have 91 feet of boards. if each foot is $1.50, we have to multiply 91 • 1.50 = 136.50 to find the total cost of the 91 feet of boards, which is $136.50.