A alone can do a work in 30 days. B alone can do the same workin 40 days. If they work on alternate days starting with A, then in how many days(correct up to two places of decimal) the work will be completed?

34.25

A = 30 days, B = 40 days,

⇒ They both work alternatively, starting with A,

 1st day =    4 units

 2nd day =   3 units

Every 2 days = 7 units completed

So, in 34 days, 119 units will be completed,

and in \( {34 }_{ 4}^{1 } \) days 120 units of work will be completed.

Therefore, it will take 34.25 days to complete the total work.