Nicole jogged for a distance and then turned around and walk

Nicole jogged for a distance and then turned around and walked back to her starting point. While jogging she averaged 7.2 miles per hour, and while walking she averaged 2.4 miles per hour. If the total time spent jogging and walking was 4 hours, find (a) how long she jogged; (b) the total distance she traveled.

Solution

Jogging DATA:
rate = 7.2 mph ; distance = x miles ; time = d/r = x/7.2 hrs
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Walking DATA:
rate = 2.4 mph ; distance = x miles ; time = d/r = x/2.4 hrs
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Equation:
time + time = 4 hrs
x/7.2 + x/2.4 = 4 hrs.
2.4x + 7.2x = 7.2*2.4*4
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9.6x = 69.12
x = 7.2 miles
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Jog time = x/7.2 = 7.2/7.2 = 1 hr
Total distance traveled = 2x = 2*7.2 = 14.4 miles