A hare spots a dog 100 m away and starts running away from it at 12 km/h. One minute later,the dog gives a chase at 16 km/h speed. At what distance from the spot where the hare took flight and the dog catch the hare?

Hare spots a dog at a distance of 100 m

Distance covered by hare in 1 min, $$ d =12 km/hr \times \frac{1}{60} $$

$$ d = \frac{1}{5} km $$

         = 200 m

Now dog has to cover total 300 m (100 + 200)

Time taken by dog to cover total 300 m , 

Relative speed = 16-12 = 4 km/hr

$$ t = \frac{300 m}{4 km/hr} $$

300 m = $$ \frac{3}{10} km $$

Solving , we get $$ t= \frac{3}{40} hr $$

Distance covered by hare = $$ 12 \times \frac{3}{40} $$

d = $$ \frac{9}{10} km $$

  = 900 m