If I understand correctly what you are trying to do, you have a total amount of work and want to allocate it in such a way that the work is allocated equally between the non-weighted workers, but Drew gets half of what one non weighted worker gets and Tim twice as much. Just compute the maths before starting: 3 workers get each 1 part, Drew gets 0.5 part, and Tim gets two parts. Total number of parts: 3 + 0.5 + 2 = 5.5. Just calculate the total amount of work, divide it by 5.5 to get the value of each part, and then assign non weighted workers 1 part, Drew 0.5 part and Tim two parts.