If Abhi travels a certain distance at 6 km/h. he reaches his destination 12 minutes early, but if he travels at 4 km/h, he reaches his destination 10 minutes late. The speed (in km/h) at which he should travel to reach his destination on time is _____.

$4\frac{5}{7}$

Let right time to Abhi to cover its journey = t min

Distance = Speed × Time

According to question ,

\(\frac{6 × (t-12)}{60}\) = \(\frac{4 × (x+10)}{60}\)

3(t - 12) = 2 ( t + 10)

t = 56 minutes

Speed of Abhi = \(\frac{6 × (56-12)}{56}\)  = \(\frac{6 × 44}{56}\)

= 4\(\frac{5}{7}\) km/h