LR — Routes, Networks & Flows
Data Interpretation and Logical Reasoning · PYQ 2017
A new one-way road is built from M to N. Each car now has three possible routes to travel from A to B: A–M–B, A–N–B and A–M–N–B. On the road from M to N, one car takes 7 minutes and each additional car increases the travel time per car by 1 minute. Assume that any car taking the A–M–N–B route travels the A–M portion at the same time as other cars taking the A–M–B route, and the N–B portion at the same time as other cars taking the A–N–B route.
If all the cars follow the police order, what is the minimum travel time (in minutes) from A to B? (Assume that the police department would never order all the cars to take the same route.)