Two cars are traveling on the same road

Two cars are traveling on the same road towards each other.  If car A is traveling at a speed of 120 Km/h and car B is traveling 15% slower, how much time will it take the cars to meet if the initial distance between the two is 668.4 Km and car A started to drive one hour and a half before car B started?

(a) one hours and 30 minutes.
(b) two hours.
(c) two hours and 12 minutes.
(d) three hours and 15 minutes.
(e) three hours and 18 minutes.

The best answer is C.
Car B is traveling at a speed of 0.85 x 120 = 102 Km/h.
Car A travels alone a distance of 120 x 1.5 = 180 Km. The remaining distance should be divided among the sum of the cars speeds: (668.4 – 180 = 488.4 Km) / (102 + 120) = 2.2 = Two hours and 12 minutes.