SOLUTION: Emily traveled 60 miles on the highway and 16 miles on the local roads to reach her destination. On the highway, she traveled 30 miles faster than on local roads. If her speed on l

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Question 1183207: Emily traveled 60 miles on the highway and 16 miles on the local roads to reach her destination. On the highway, she traveled 30 miles faster than on local roads. If her speed on local roads is 20 miles per hour, then what was her average speed, in miles per hour, during her entire trip?
Found 2 solutions by ikleyn, josgarithmetic:
Answer by ikleyn(52775) About Me  (Show Source):
You can put this solution on YOUR website!
.
Emily traveled 60 miles on the highway and 16 miles on the local roads to reach her destination.
On the highway, she traveled 30 miles faster than on local roads.
If her speed on local roads is 20 miles per hour, then what was her average speed, in miles per hour, during her entire trip?
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Average speed is the entire travel distance divided by the whole travel time.


The entire distance is 60+16 = 76 miles.


The time traveled on highway was 60%2F%2820%2B30%29 = 60%2F50 = 6%2F5  of an hour.


The time traveled on the local road was  16%2F20 = 4%2F5  of an hour.


The total time was  6%2F5 + 4%2F5 = 10%2F5 = 2 hours.


The average speed is  76 miles divided by 2 hours = 76%2F2 = 38 miles per hour.    ANSWER

Solved.


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Comment from student : 𝑣 =(60+16)/(60/(30+20)+16/20) v=76/(60/50+4/5) v=76/(6/5+4/5) v=76/((10/5)) v=76/2=38 miles per hour



My response :   Honestly,  I didn't get for what reason you posted me this comment.




Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
You mean, she traveled 30 miles per hour faster than on local roads? 
                 SPEED miles per hour   TIME hours        DISTANCE miles

Highway           20+30                 60/50=6/5              60

Local              20                   16/20=4/5              16

TOTALS                                    10/5=2               76

Average speed for total trip, %2876%2F2%29%28miles%2Fhour%29=highlight%2838%28miles%2Fhour%29%29