In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: annika hikes at a constant rate of 12 minutes per kilometer . she has hiked 2.75 kilometers east from the start of a hiking trail when she realizes that she has to be back at the start of the trail in 40 minutes . if annika continues east , then turns around and retraces her path to reach the start of the trail in exactly 40 minutes , for how many kilometers total did she hike east ? 
Options: a ) 3.625 , b ) 3.5 , c ) 3 , d ) 3.04 , e ) 4
[EX A]: d

[EX Q]: Problem: a constructor estimates that 3 people can paint mr khans house in 4 days . if he uses 4 people instead of 3 , how long will they take to complete the job ? 
Options: a ) 2 , b ) 8 , c ) 1 , d ) 3 , e ) 4
[EX A]: d

[EX Q]: Problem: a circular path of 12 m radius has marginal walk 2 m wide all round it . find the cost of leveling the walk at 50 p per m 2 ? 
Options: a ) rs . 49 , b ) rs . 40 , c ) rs . 81.72 , d ) rs . 42 , e ) rs . 43
[EX A]:
c