Answer :
Mohan's (can do) = (12 days)
Mohan's (1day) = 1/12 (work)
Sohan's = 60% ( more efficient then Mohan)
Sohan's (1 day ) = 1/12 + 60/100x(1/12) (work)
= 1/12 + 6/10X1/12
= 1/12 + 1/20 =(5+3)/60 = 8/60 = 2/15
Sohan's (1 day ) = 1/7.5 (work)
Sohan's (7.5) day = 1 (finish the work)
Mohan's (1day) = 1/12 (work)
Sohan's = 60% ( more efficient then Mohan)
Sohan's (1 day ) = 1/12 + 60/100x(1/12) (work)
= 1/12 + 6/10X1/12
= 1/12 + 1/20 =(5+3)/60 = 8/60 = 2/15
Sohan's (1 day ) = 1/7.5 (work)
Sohan's (7.5) day = 1 (finish the work)