Two car A and B starts from city P and Q respectively towards each other. The distance between the city P and city Q is 100 kilometers. Find the time after which the distance between the cars will be 20 kilometers after meeting if the speed of car A is 30 kmph and car B is 20 kmph.
1
120 minutes
2
124 minutes
3
132 minutes
4
144 minutes
5
140 minutes