28. A garrison of 500 men had provisions for 24 days. However, a reinforcement of 300 men arrived. The food will now last for :

29. If 300 men can do a piece of work in 16 days, how many men would do (1/5) of the work in 15 days ?

30. A contractor undertakes to do a piece of work in 40 days. He engages 100 men at the beginning and 100 more after 35 days and completes the work in stipulated time. If he had engaged the additional men, how many days behind schedule would it be finished ?