Correct. But if one sells 1/2 of the original and then 1/3 of the remaining, then 1/3 is left. 1 whole =6/6 1/2 of 6/6 = 3/6 (remaining) 1/3 of 3/6 = 1/6 3/6 - 1/6 = 2/6 2/6 = 1/3 left after both sales.