Keshav and Madhav decide to take up a project to complete together in 35 days while Keshav alone can finish the project in 84 days. But due to the non-availability of space, they decided to work on alternate days, Keshav working on day 1 and Madhav working on day 2 and day 3 and so on. In how many days will they complete the project?
1
\(70 \frac{25}{42}\)
2
\(62 \frac{11}{21}\)
3
\(66 \frac{2}{5}\)
4
\(64 \frac{6}{35}\)