A,B,C can do a piece of work in 36,54,and 72 days respectively. they started the work but A left 8 days before the completion of the work while B left 12 days before the completion. the number of days for which c worked is?
You may find number of approaches for such questions. I personally find below method to be shortest.
A=36
B=24
C=72.
Take LCM of these numbers to get 18X12.
So A will finish 18X12/36=6 units in 1 day, similarly B=4 units, C=3 units.
Let total work to be completed is 18X12(This is imp number to choose)
Let C worked for x days
so A worked for x-8, B for x-12, C for x
so A's Rate X Days Worked + .... = total work
6(x-8)+4(x-12)+3x=18X12, solve for x to get 24.
I know this method works well, but I have a general question , is it OK to assume two values in one linear equation, here we assumed, 18X 12 and x, had it been ratio or similar, the assumed expression might have got canceled.Please comment.
