Two cars P and Q start at the same time from A and B which are 120 km apart. If the two cars travel in opposite directions, they meet after one hour and if they travel in same direction (from A towards B), then P meets Q after 6 hours. What is the speed of car P? Choose the correct choice from the following options
A) 75 km/hr B) 71 km/hr C) 72 km/hr D) 70 km/hr E) 78 km/hr
D   70 km/hr   Let their speed be x km/hr and y km/he respectively.   Then, 120/(x + y) = 1 =&gt; x + y = 120 --- (i)   Now, when they move in same direction:   (70 km/hristance traveled by P in 6 hrs) - (70 km/hristance traveled by Q in 6 hrs) = 120 km   6x - 6y = 120 =&gt; x - y = 20 --- (ii)   Sloving (i) and (ii), we get x = 70, y = 50   P's speed = 70 km/hr.
<result>D</result>
Two cars P and Q start at the same time from A and B which are 120 km apart. If the two cars travel in opposite directions, they meet after one hour and if they travel in same direction (from A towards B), then P meets Q after 6 hours. What is the speed of car P?