Truck P and Truck Q drive on the highway in the same direction at respective rates of 72 kph and 80 kph. If Truck Q is 5 km behind Truck P, by how much does Truck P need to increase the speed to catch up with Truck P in 20 minutes?  Answers:	A) 6 kph	B) 7 kph	C) 8 kph	D) 9 kph	E) 10 kph
Truck Q needs to gain 5 km in 20 minutes.   The relative speed difference needs to be 5 km / 20 minutes = 15 km/hour   Truck Q needs to increase up to 87 kph, thus an increase in 7 kph.   The answer is 7 kph.
<result>B</result>
Truck P and Truck Q drive on the highway in the same direction at respective rates of 72 kph and 80 kph. If Truck Q is 5 km behind Truck P, by how much does Truck P need to increase the speed to catch up with Truck P in 20 minutes?