Question 1142664
To prepare for a marathon​ run, Sue ran 30 miles before she blistered her​ heel, and then she walked 1 additional mile. Her running speed was 12 times as fast as her walking speed. She was running and walking for 7 hours. Find​ Sue's running speed.
-------
r = run speed
w = walk speed
-------
30/r + 1/w = 7
r = 12w
-----
30/12w + 1/w = 7
30/12 + 1 = 7w
7w = 3.5
w = 0.5 mi/hr
r = 6 mi/hr