15 persons working 8 hours a day can complete a work in 21 days. How many days will 14 persons take to complete a work `1 1/2` times as great, if they work 6 hours a day?

15 persons working 8 hours a day can complete a work in 21 days.How many days will 14 persons take to complete a work 1(1)/(2) xx as great,if they work 6 hours a day?

Thirty persons working 6 hours a day can complete a work in 28 days. How many days will 28 persons take to complete another work which is two times the present work, if they work 9 hours a day?

10 men working 6 hours a day can complete a work in 18 days. How many hours a day must 15 men work to complete the same work in 12 days.

10 men, working. 6 hours a day can compJete a work in 18 days. How many hours a day must 15 men work to complete the same work in 12 days?

10 men working 8 hours day can do a work in 30 days. In how many days will 12 men working 4 hours a day take do the same work?