SOLUTION: Jerry’s parents live 55.0 km exactly west from his home. On one trip from his house to his parent’s home, he takes 1.25 hrs. to complete the journey. On arrival, he forgot he

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Jerry’s parents live 55.0 km exactly west from his home. On one trip from his house to his parent’s home, he takes 1.25 hrs. to complete the journey. On arrival, he forgot he       Log On

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Question 1164303: Jerry’s parents live 55.0 km exactly west from his home. On one trip from his house to his parent’s home, he takes 1.25 hrs. to complete the journey. On arrival, he forgot he had to pick up some groceries, and so immediately, he drives 22.0 km east to a grocery store in a time of 0.40 hrs. Determine the average speed of Jerry (in units of m/s) for his entire trip from his home to the grocery
store.

Found 2 solutions by Shin123, ikleyn:
Answer by Shin123(626) About Me  (Show Source):
You can put this solution on YOUR website!
Jerry drove a total of 55%2B22=77 km and it took him 1.25%2B0.4=1.65 hours to do so. 1.65 hours is equivalent to 1.65%2A60%2A60=5940 seconds and 77 km is equal to 77,000 m. So Jerry's average speed is 77000%2F5940 m%2Fs, which is about 12.963 m/s.

Answer by ikleyn(52810) About Me  (Show Source):
You can put this solution on YOUR website!
.

The average speed for the total trip is the sum of traveled distances divided by the total travel time


    V%5Baverage%5D = %2855+%2B+22%29%2F%281.25+%2B+0.4%29 = 46.666... km/h = 46 2%2F3 km/h.      ANSWER


Your problem, as it is worded and printed, contains some portion of an unnecessary information.

Namely, pointing "east' and "west" is irrelevant.

Jerry may drive in any direction without changing the answer.


It makes bad impression about a composer, when a Math problem contains unnecessary info.


Sometimes it is good and is appropriate for educational purposes, but not in this case.