Four persons can build a wall in 12 days . How many persons will be required to build the same will in 8 days.

Fifteen men can build a wall in 60 days. How many more men are required to build another wall of same size in 45 days ?

Twelve persons can do a piece of work in 20 days. How many persons are required to do the same in 24 days?

If 36 workers can build a wall in 12 days, how many days will 16 workers take to build the same wall ? (assuming the number of working hours per day is constant)

If 15 workers can build a wall in 48 hours.How many workers will be required to do the same work in 72 hours?

If 56 workers can build a wall in 180 hours, how many workers will be required to do the same work in 70 hours ?

3 persons can build a wall in 4 days, then 4 persons can build it in

24 workers can build a wall in 15 days. How many days will 9 workers take to build a similar wall?