A boy has to cover 4km to caught a bus.He part of the distance at 3km/h and ran the rest at 5m/h if he takes 1hour to complete the distance for how many km does he walk
Let's assume that the boy walked x km at 3 km/h and ran (4-x) km at 5 km/h.
We know that the total time taken by the boy to cover the distance is 1 hour.
So, the time taken to walk x km at 3 km/h is x/3 and the time taken to run (4-x) km at 5 km/h is (4-x)/5.
Therefore, we can write the equation:
x/3 + (4-x)/5 = 1
Multiplying both sides by 15, we get:
5x + 3(4-x) = 15
Simplifying the equation, we get:
5x + 12 - 3x = 15
2x = 3
x = 1.5 km
Therefore, the boy walked 1.5 km at 3 km/h and ran 2.5 km at 5 km/h.