For this case we have to:
The circumference or perimeter of a circle is given by:

where d is the diameter of the circle.
Substituting the given value of c,
, we have:


Therefore, the diameter of the circle is 6m.
Answer:
Option C
Answer:
2
Step-by-step explanation
If you convert 2/7 to an equivalent fraction, you would get 4/14. Add 4/14 to 13/14 to get 17/14 or 1 and 3/14
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