A team from the highway department can replace 14 streetlights in 7 hours of work. If they work a 30-hour week at this job, in how many weeks will they replace all 120 downtown streetlights?
Correct Answer: B
Rationale: If the team can replace 14 streetlights in 7 hours, it means they replace 2 streetlights per hour. In a 30-hour week, they can therefore replace 2 x 30 = 60 streetlights. To replace all 120 downtown streetlights, they will need 120 / 2 = 60 hours, which is equivalent to 60 / 30 = 2 weeks. Therefore, the correct answer is 2 weeks. Choice A, 1½ weeks, is incorrect because it doesn't consider the total number of streetlights that need to be replaced. Choice C, 2½ weeks, is incorrect as it overestimates the time needed. Choice D, 3 weeks, is incorrect as it underestimates the efficiency of the team in replacing streetlights.