Question 868419
Anuj alone does the job in 20 days.
every third day he takes help

so he takes help on 6 days

anuj does 1/20 of job in 1 day

and on 6 days they do 1/20+1/30+1/60 of the job = 1/10 of the job

On 6 days they do 6/10 of the job
and on 14 days 14/20 of the job is done

in 20 days they can do 6/10 + 14/20 of the job
=26/20 of the job in 20 days

so 26/20 of the job 20 days
1 job = 400/26= 15.38 days