Bus a and bus b leave school on a field trip when a stopwatch reads zero. bus a travels at a constant 50 km/h, and bus b travels at a constant 75 km/h. how far are the two buses from school when the stopwatch reads 1.5 h? . a.. bus a is 76.5 km from school, bus b is 51.5 km from school. c.. bus a is 75 km from school, bus b is 112.5 km from school. b.. bus a is 112.5 km from school, bus b is 75 km from school. d.. bus a is 51.5 km from school, bus b is 76.5 km from school