A dog saw a cat at a distance of 280 m. The cat started running at the speed of 10 km/h and the dog also ran to catch it with the speed of 24 km/h. How much time will the dog take to catch the cat?

1.2 min

We know that ,

Speed = \(\frac{Distance}{Time}\)

To convert km/h into m/sec

10 km/h = 10 × \(\frac{ 5 }{18}\) m/sec = \(\frac{ 25 }{9}\) m/sec

24 km/h = 24 × \(\frac{ 5 }{18}\) m/sec = \(\frac{ 20 }{3}\) m/sec

As both moves in same direction,

So relative speed = \(\frac{ 20 }{3}\) - \(\frac{ 25 }{9}\)

= \(\frac{ 60 - 25  }{9}\)

= \(\frac{ 35 }{9}\) m/sec

Time = \(\frac{ 280 × 9 }{35}\)

= 72 seconds

= 1.2 minute