Can any1 solve this?( dnt knw the answr)A contractor has undertaken to complete a job in 30 days. 70 ppl were working on day 1. but he found the work was not completed in the given time. He hires 5 ppl more on 2nd day ,on 3rd day 2 ppl ran away..on next day he hires 5 more & again 2 runs...........till 40th day.How many ppl should have bought on 1st day so that no one ran & also the job is completed on 30th day??

1) a
2) b
3) c