Anil and Sunil can complete a job in 15 days and 20 days respectively. Both of them started it together. Anil left 6 days before the work was completed. Find the time taken (in days) to complete the work.
Let total work is LCM of (15, 20) = 60
Work done by Anil in a day = 4 units
Work done by Sunil in a day = 3 units
Anil worked for (t – 6) days and Sunil worked for t days.
4(t – 6) + 3t = 60
t = 12; Option (c).
2nd method:- during last 6 days sunil alone will work i.e 30% of work will be done by sunil alone. Remaining 70% of work will be done together. In one day both will do (10015)+(10020)=11.67% , then 70% will complete in 6 days. Total 6+6= 12 days.Option (c).