SOLUTION: A man jogged in 3.5 km in 20 min. He then walked the remainder of the 5.5 km at an average speed of 5km/h. Given that he did not stop to rest duting the entire distance of 5.5 km,

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: A man jogged in 3.5 km in 20 min. He then walked the remainder of the 5.5 km at an average speed of 5km/h. Given that he did not stop to rest duting the entire distance of 5.5 km,       Log On


   

Question 1020008: A man jogged in 3.5 km in 20 min. He then walked the remainder of the 5.5 km at an average speed of 5km/h. Given that he did not stop to rest duting the entire distance of 5.5 km, calculate his average speed in km/h for the whole journey.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Average speed = [ total distance ] / [ total time ]
Total distance = +5.5+ km
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For the 2nd part of the trip:
+5.5+%2F+5+=+1.1+ hrs
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Convert min to hrs
+20%2F60+=+1%2F3+
Total time = +1%2F3+%2B+1+%2B+1%2F10+
Total time = +10%2F30+%2B+30%2F30+%2B+3%2F30+
Total time = +43%2F30+
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+5.5+%2F+%28%28+43%2F30+%29%29+=+%28+30%2F43+%29%2A5.5+
+%28+30%2F43+%29%2A5.5+=+3.837+
average speed = 3.837 km/hr