A person covers a distance of 47 km in 7 hrs . Some part of this journey is covered on foot at the speed of 5 km/hr and the rest by cycle at the speed of 8 km/hr. Find the distance covered on foot .

15

Distance = Speed × Time 

Total Distance = 47 km 

Total Time taken = 7 hours 

Let the time he traveled on foot be x hours with speed 5 km/hr 

And time he traveled by bicycle is ( 7 - x ) hours with speed 8 km/hr 

According to question , 

5 × x + 8 × ( 7 - x ) = 47 

5x + 56 - 8x = 47 

3x = 9    ⇒   x = 3 hours 

So ,  distance traveled by foot = 5  ×  3 = 15 km