Two planes approach head-on. Each has a speed of 800 km/h, and they spot each other when they are initially 20 km apart. How much time do the pilots have to take evasive action?
PLEASE HELP ME UNDERSTAND HOW TO DO THIS PROBLEM, THANK U

Sorry-------- too much for me to help you Bella :confused:

speed=\frac{distance}{time}

remember that they only have half the distance to travel before they crash.