There is a circular path around a sports field. Sonia takes 18 minutes to drive one round of the field, while Ravi takes 12 minutes for the same. Suppose they both start at the same point and at the same time, and go in the same direction. After how many minutes will they meet again at the starting point ?

Two heater coils separately take 10 minutes and 5 minutes to boil a certain amount of water.Find the time taken by both the coils connected in series to boil the same amount of water.

Two person can finish the work in 7 days. (i) One of the persons fell ill before the work started . How much time will the other person take to finish the same work. (ii) How many persons will be needed to finish the work in one day.

Points A and B are 90 km apart from each other on a highway. A car starts from A and another from B at the same time. If they go in the same direction they meet in 9 hours and if they go in opposite direction they meet in 9/7 hours. Find their speeds.

From the pair of linear equations in the following problems and find their solutions (if they exist) by elimination method : Points A and B are 90 km apart from each other on a highway. A car starts from A and another from B at the same time. If they go in the same direction they meet in 9 hours and if they go in opposite direction they meet in 9/7 hours. Find their speeds.

A and B are two points of 150 km apart on a highway. A car starts from A and another from B at the same time. If they move in the same direction, they meet in 15 hours, but if they move in opposite direction, they meet in one hour. Find their speeds.

Two cars are 351 km apart. They start at the same time and drive towards each other. One travels at 70 km/hr and the other travels at 65 km/hr. How much time do they take to meet each other?

Form the pair of linear equations in the following problems and find their solutions (if they exist) by any algebraic method :-Places A and B are 80 km apart from each other on a highway. A car starts from A and another from B at the same time. If they move in the same direction they meet in 8 hours , and if they move in opposite direction, they meet in 1 hour and 20 minutes respectively. Find the speed of the cars.

Two cars start together in the same direction at the same place.The first goes with the speed of 10km/hr. The second goes at the speed of 8 km/hr in the first hour and increases the speed by 1/2 km each succeeding hour. After how many hours will the second car overtake the first if both cars go non-stop ?

Two boatmen start simultaneously from the opposite shore of a river with same speed and they cross eachother after 45 minutes of their starting from the respective shores. They rowed till theyreached the opposite shore and returned immediately after, reaching the shores. When willthey cross each other again?