Group Work  
Group work Calculation

Where,
a > Work done by A in days or hours
b > Work done by B in days or hours
Example:
Calculate the time taken by A and B to complete a work together.
A can complete a work in: 2 in days or hours
B can complete a work in: 1 in days or hours
Solution:
Apply Formula:
Group work = ((1 / a) + (1 / b)).
Group Work = (½) + (1/1)
Group work = 0.5 + 1