Average speed is ALWAYS calculated as total distance / total time
<span>total distance is 100mi </span>
<span>total time is (50mi / 33) + (50mi / 80) </span>
<span>total time is = 1.52 + 0.625 = 2.145 </span>
<span>so average speed going to grandmothers house is 100mi / 2.145 hrs = 46.62 mph </span>
<span>on her return trip </span>
<span>x = V1 x t/2 + V2x t/2 </span>
<span>100 = 33t/2 + 80t/2 </span>
<span>100 = 113t/2 </span>
<span>t = 100x2/113 = 1.7699hrs </span>
<span>average speed = 100mi/1.7699hrs = 56.60mph</span>
Answer:
B i believe
Step-by-step explanation:
