If A can do a piece of work in X days, then A’s one day’s work = 1/X part of whole work.
If A’s one day’s work = 1/X part of whole work, then A can finish the work in X days.
If A can do a piece of work in X days and B can do it in Y days then A and B working together will do the same work in XY/(X + Y) days.
If A, B and C can do a work in X, Y and Z days respectively then all of them working together can finish the work in XYZ/(XY + YZ + XZ) days
New Tricks and Questions:
I have evaluated the new and fast concept to solve Time and Work questions which can help you in your exams where to beat the clock is essential to crack the exam. So, you can download the PDF in which all important with solutions are mentioned with new and efficient trick to solve these types of questions.