Practicing Success
Places A and are 45 km apart from each other. A car starts from place A and another car starts from place at the same time. If they move in the same direction, they meet in 4 and a half hour and if they move towards each other, they meet in 27 minutes. What is the speed (in km/h) of the car which moves faster? |
56 55 45 50 |
55 |
Let speed of faster car = x km/h Speed of slower car = y km/h Relative speed when car moves in same direction = ( x - y ) km/h Relative speed when car moves in opposite direction = ( x + y ) km/h According to question , \(\frac{45}{x - y }\) = 4.5 ( x - y) = 10 --------(1) Now , \(\frac{45}{x + y }\) = \(\frac{27}{60}\) \(\frac{45}{x + y }\) = \(\frac{9}{20 }\) ( x + y) = 100 ( x+ y) = 100 -------(2) Adding equation 1 & equation 2 2x = 110 x = 55 So , the speed of faster car is 55 km/h . |