A contractor undertook to complete a piece of work in 40 days. He engages 100 men at the beginning and 100 more men after 35 days, and completes the work in the stipulated time. If he had not engaged the additional men, how many days behind schedule would the work have been finished?

If 18 men working 7 hours a day can prepare 14 school uniforms in 20 days, then in how many days can 12 men working 6 hours a day prepare 18 school uniforms?

Raju alone can complete a work in 36 days, and Raj alone can complete the same work in half the time taken by Raju. How many days will they take together to complete 14 of the total work?