A certain sum of money is borrowed by a person at 8% simple interest for 4 years. If he has to pay 7384 as interest, what is the total amount he has to pay ?

Two trains 80 metres and 70 metres in length respectively are running in the same direction on parallel tracks. The speed of the first train is 45 km/h and that of the second train is 36 km/h. In what time will they be completely clear of each other from the moment they meet ?

A man can row 12 km/h in still water. If the river is running at 3 km/h, it takes 6 hours more upstream than to go downstream for the same distance. How far is the place ?