SOLUTION: Two families from the same neighborhood plan a ski trip together. The first family makes the 455 mile trip at a speed 5 miles per hour faster than the second family. The second f

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Question 1170442: Two families from the same neighborhood plan a ski trip together. The first family makes the 455 mile trip at a speed 5 miles per hour faster than the second family. The second family takes a half-hour longer to make the trip. What are the speeds of the two families?

Found 2 solutions by ikleyn, josgarithmetic:
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
Two families from the same neighborhood plan a ski trip together. The first family makes the 455 mile trip
at a speed 5 miles per hour faster than the second family. The second family takes a half-hour longer to make the trip.
What are the speeds of the two families?
~~~~~~~~~~~~~~


Sorry,  looking into your post,  I can not believe/trust to my eyes,
and therefore,  I would like to ask again:


                How many miles is/was the ski trip ?


/\/\/\/\/\/\/\/

Regarding the post by @josgarithmetic,  do not consider it seriously,

since it may harm your common sense,  your psychic and your brain.



Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
                SPEEDS         TIME         DISTANCE

FirstFam         r+5           455/(r+5)     455

SecFam           r             455/r         455

Difference                     1/2

Accounting for given time difference,
455%2Fr-455%2F%28r%2B5%29=1%2F2
algebra steps
.
.
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r%5E2%2B5r-4550=0

Discriminant is 135%5E2 so use of general solution for quadratic equation gives
r=%28-5%2B135%29%2F2
highlight%28r=65%29-----------speed for the SECOND family.
r%2B5=highlight%2870%29---------speed for the FIRST family.