Train A:
Distance (s) = 420 miles
Time (t) = 3 hours
Speed (v) = distance ÷ time = 420 ÷ 3 = 140 miles/hour
Train B:
Distance (s) = 420 miles
Time (t) = 2.25 hours
Speed (v) = distance ÷ time = 420 ÷ 2.25 = 186.7 miles/hour
Answer:

Step-by-step explanation:
CD is perpendicular to AB
If any radius or diameter is perpendicular to any chord of a circle, then it bisects that chord.
Mean, AB= BE = 12
So, AB = 2(BE)
2(12)= 24
so your answer will be 24

hope it helps..
have a great day!!