Question

If government wants to ensure that all motorists travelling from S to T pay the same amount (fuel costs and toll combined) regardless of the route they choose and the street from B to C is under repairs ( and hence unusable), then a feasible set of toll charged (in rupees) at junctions A, B, C and D respectively to achieve this goal is:

• A. 2,5,3,2
• B. 0,6,3,1
• C. 1,5,3,2
• D. 2,3,5,1

Answer 1

The correct option is C 1,5,3,2

Available routs are
SAT $\to$ Rs. 14
SBAT $\to$ Rs. 9
SDCT $\to$ Rs. 10
SDT $\to$ Rs. 13
Now fuel cost of SAT - fuel of SDT = 14 - 13 = Rs. 1. Hence, toll at junction D should be 1 more than the toll at junction A.
So, option (a) and (d) are ruled out.
Now fuel cost of SAT - fuel cost of SBAT = 14 - 9 = Rs. 5.
So, toll at junction B should be Rs. 5, which is there in option (c).