So you subtract the fractal amounts from the whole with all of his customer being 1 and adding all the fractions 1-(1/8+2/5+3/10) 1-(1/8+4/10+3/10) 1-(1/8+7/10) 1-(5/40+28/40 1-(33/40) 1=40/40 40/40-33/40 7/40 of his customers chose a natural finish
They most likely wanted slaves to be afraid so they did not collect the courage to escape or disobey. With low self esteem they might not try anything.