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
So you are arguing that the width is immaterial and that the boards were sold by the linear foot, not by the area?
OK, I can buy that.
What IS suspicious about this question is that the price is ridiculously high for 1895, and looks more like a current price.
$3901.44 would be about 9 years worth of average wages in 1895. Seems a little steep for 640 sq ft of planking!