Problem: K takes 30 minutes less time than M to travel a distance of 30 miles. K travels 31 mile per hour faster than M. If x is K 's rate of speed in miles per hour, then K 's time for the distance is:
Answer Choices:
A. 30x+31
B. 30x−31
C. x+3130
D. x30
E. 30x
Solution:
Time = distance / rate; ∴t=30/x.