If a person travels at a speed of 56 km/h, he will reach his destination on time.  He covers \(\frac{3}{4}\)th of his journey in \(\frac{3}{7}\)th of time.  At what speed (in km/h) should he travel to cover the remaining distance to reach his destination on time?

24.5

D = S × T

Let, Time is 7 hours 

Distance = 56 × 7 = 392,

Here, He covers \(\frac{3}{4}\)th of his journey in \(\frac{3}{7}\)th of time

Now, We have to find the speed to cover the remaining \(\frac{1}{4}\)th journey in \(\frac{4}{7}\)th of the time.

Therefore,

Speed          Time            Distance

   56                7                392

                       ↓                   ↓

                     ×\(\frac{4}{7}\)               ×\(\frac{1}{4}\)

                      ↓                    ↓

                      4                  98

Speed for remaining journey = \(\frac{98}{4}\) = 24.5 km/h