Answer:
2 miles
Step-by-step explanation:
Their combined speed (speed of closure) is 80 mph + 40 mph = 120 mph.
120 mi/h = 120 mi/(60 min) = 2 mi/min
The distance between the trains at the 1-minute mark is ...
(1 min) · (2 mi/min) = 2 mi
They were warned when two miles apart.
7/8 / 11/12. First get the reciprocal of 11/12 (which is 12/11). Then multiply by the reciprocal. 7/8 * 12/11 = 84/88
don't forget to simplify
21/22