Question 199321
If Sam can do a job in 4 days and Lisa can do it in 6 days and tom in 2 days,
 how long would the job take if Sam, Lisa and Tom worked together to complete it?
:
Let t = time required if all three work together
Let the completed job = 1
:
{{{t/4}}} + {{{t/6}}} + {{{t/2}}} = 1
Multiply equation by 12 to get rid of the denominators, results:
3t + 2t + 6t = 12
11t = 12
t = {{{12/11}}} days or (12/11) * 24 ~  26.2 hrs