Question 1177288


radar detected an unidentified plane 5000 km away, approaching at 700 kph.

In 1/4 hour the plane wouldbe nearer by d= speed * time 
700*1/4 = 175 km

5000-175 = 4825

 Fifteen minutes later, = 1/4 hour 

an interceptor plane was dispatched, travelling at 800 kph.

Both planes approaching each other.
Effective speed = 700+800 =1500 kph

Distance between them = 4825 km

time = distance / speed

= 4825/1500

= 3.22 hours




 the interceptor take 3.22  hours to reach the approaching plane