Neco Model Questions Vol1 2021 Economics Question 45

A city is evaluating a new highway that would connect point A directly to point D. The existing road network gives the following travel times (in minutes): A‑B = 30, B‑C = 20, C‑D = 25, A‑C = 55, B‑D = 45. The proposed highway would have a travel time of \(t\) minutes. There are 10,000 commuters who travel from A to D each day and 5,000 commuters who travel from A to C each day. If the highway is built, commuters will choose the fastest route. Each minute saved per commuter is valued at N5,000. The construction cost of the highway is N10,000,000. Determine the greatest value of \(t\) (in minutes, to one decimal place) for which the project is economically justified (i.e., total benefit ≥ construction cost).