Answer:D Explanation:Let's calculate how much time it takes to repair the road if just 1 person were working on it. 5 hours a day for 12 days makes it 60 hours per person. 39 people working 60 hours each makes it 39*60=2340 hours in total. Now we have 30 people working 6 hours a day That means 30*6=180 hours are spent each day. We need a total of 2340 hours. With 180 hours every day, that's going to take 2340/180 = 13 days to complete... Or you could just do it in one step... :- 39*12*5 = 30*X*6 2340 = 180X X = 2340/180 X = 13.

A certain number of men complete a piece of work in 60 days. If there were 8 men more, the work could be finished in 10 days less. How many men were originally there?

A train 150 m long is running with a speed of 68 kmph. In what time will it pass a man who is running at 8 kmph in the same direction in which the train is going?