A. 63

B. 75

C. 83

D. 126

E. 188

**My problem is that answers coming differently if I adopt different methods. What am I doing wrong ?**

Solution A:

Total distance to be covered by both cars approx = 2 x 3.14 x 20 = 125.6 miles

Since car A has already left 20 mint ago - it has already travelled = 20 miles

The distance now remained to be covered by both cars is approx = 106 miles

Car B now starts after 20 mints

(Relative Rates) x T = total dist to be covered

100T = 100.6

T=1.06 .. approx 63 mints

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Solution B:

Distance by Car A + Distance by Car B = Total Distance

60T + 40(T-20/60) = 125.6

100T - 40/3 = 125.6

T = 1.39

approx = 83 minutes

Correct answer is 83 and not 63 mintes - whats the difference b/w two solutions. I got this wrong since I used Solution A.