50 villages had taken 18 days to dig a pond . Calculate by using theory of variation how many extra persons will be required to dig the pond in 15 days.

30 workers can dig a trench in 5 days. How many workers will be required to dig it in 6 days?

2 men can cultivate 6 acres of land in 4 days . By using theory of variation , find the number of men required to cultivate 18 acres of land in 8 days.

50 labourers can dig a point in 16 days. How many labourers will be reuired to dig another pond, double in size, in 20 days ?

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

If 15 farmers can cultivate 18 bighas of land in 5 days, then calculate by using thoery of variation the number of days required by 10 farmers to cultivate 12 bigas of land.

15 men can cultivate 18 bighas of land in 5 days. By using theory of variation, determine the number of bighas to be cultivated by 10 men in 10 days.

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