Three people A, B and C can do a job alone in 10 days, 12 days and 15 days respectively. In how many days they can finish the job working together?
4 days
Amount of work that can be done in day of A, B and C are 110,112 and 115 respectively.
One day worth of work that can be done if they work together is
=(110+112+115)=1560=14
∴ Time required to complete the job
=114=4 days