The complete question is <span>Sarah rides her horse for 2 1/6 hrs with a constant speed of 6 km/hr and then for another 2 hours and 5 minutes with a constant speed of 12 km/hr what is her average speed for the total trip?</span>
we know that speed=distance/time
1) Sarah rides her horse for 2 1/6 hrs with a constant speed of 6 km/hr time=2 1/6 hrs----> 13/6 hrs speed=6 km/h distance=speed*time----> 6*(13/6)---> 13 km
2)for another 2 hours and 5 minutes with a constant speed of 12 km/hr time=2hrs+5 minutes----> 2+(5/60)--> 125/60 hrs speed=12 km/hrs distance=speed*time----> 12*(125/60)---> 25 km
3) find the average speed for the total trip total distance=13 km+25 km----> 38 km total time=(13/6)+(125/60)----> (10*13+125)/60----> 4.25 hours speed=38/4.25----> 8.94 km/hrs
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