A builder appoints three construction workers Jai, Naresh and Sunil on one of his sites. They take 20, 30 and 60 days, respectively, to do a piece of work. How many days will it take Jai to complete the entire work if he is assisted by Naresh and Sunil together on alternate days? Jai starts the work on the first day alone.
1
14 days
2
\(12\frac{1}{2}\) days
3
\(13\frac{1}{2}\) days
4
10 days