Karthik walks at 5 km/hr and reaches his destination 8 min late. If he walks at 6 km/hr, he reaches his destination on time. What distance he will cover in given time ?

Let the actual distance be t kms

Now, According to the data,

$5t + \frac{8}{60} = 6t=> 5\frac{60t + 8}{60} = 6t=> 60t + 8 = 72t=> 8 = 12t=> t = 8/12 = 2/3 \mathrm{hrs}$

Now, the total distance = 6t = 6 x 2/3 = 2 x 2 = 4 kms.