Everyone is questioning the use of a metric measurement but is failing to note that the question is incongruous, The student is asked to quantify an area by a linear measurement. That doesn't make sense.
What is the cost of 40 boards 12 inches wide and 16 ft.. Long at $20 per metre?
40 x 16 = 640 linear feet
1 foot = 0.3048 meters
640 feet x 0.3048 = 195.072 meters
195.072 meters x $20 per meter = $3901.44