TIME AND WORK

Work to be done is usually considered as one unit. Work can be in any form like building a wall, making a road, filling or emptying a tank or even eating a certain amount of food.

Time is measured in hours, days etc., Certain assumptions are made that the work so done
is uniform and each person shares the same work time in case of group work in completing
the work.

Unitary Method:

If two persons X and Y can complete some work individually in a and b days, then their
one day’s work will be 1 / a and 1 / b respectively.

Working together, their one day’s work = 1 / a + 1 / b = ab / (a + b) and so, X and Y together can complete the work in ab / (a + b) days.