A and B can do a work in 20 days and 30 days respectively. A and B work on alternate days. Find the number of days to complete the work

A and B can do a work in 30 days and 10 days respectively. If they work on alternate days beginning with A, in how many days will the work be completed?

A and B can do a work in 30 days and 10 days respectively. If they work on alternate days beginning with A, in how many days will the work be completed?

Vinay and Varma can do a work in 30 days and 60 days respectively. If they work on alternate days beginning with Vinay, in how many days will the work be completed?

Vinay and Varma can do a work in 30 days and 60 days respectively. If they work on alternate days beginning with Vinay, in how many days will the work be completed?

A and B can do a piece of work in 20 days and 12 days respectively. A started the work alone and then after 4 days B joined him till the completion of the work. How long did the work last?