A person covers a distance of 24 km in 7 hours . Some part of this journey is covered on foot at the speed of 3 km/hr and the rest by cycle at the speed of 4 km/hr. Find the distance covered on foot .

12 km

Distance = Speed × Time 

Total Distance = 24 km 

Total Time taken = 7 hours 

Let the time he traveled on foot be x hours with speed 3 km/hr 

And time he traveled by bicycle is ( 7 - x ) hours with speed 4 km/hr 

According to question , 

3 × x + 4 × ( 7 - x ) = 24 

3x + 28 - 4x = 24 

x = 4 hours

So ,  distance traveled by foot = 3  ×  4 = 12 km