document.write( "Question 1175277: Practice Age word Problem\r
\n" ); document.write( "\n" ); document.write( "Ariana started biking to the library traveling 14 mph, after some time the bike got a flat so Ariana walked the rest of the way, traveling 7 mph. If the total trip to the library took 11 hours and it was 119 miles away, how long did Ariana travel at each speed?
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Algebra.Com's Answer #800927 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "You have received two response showing similar formal algebraic solutions.

\n" ); document.write( "Here is a very different path to the answer that I personally find much faster and easier (if a formal algebraic solution is not required).

\n" ); document.write( "This is essentially a mixture problem -- you are mixing some number of hours at 14mph with some number of hours at 7mph and ending up with a total of 119 miles in 11 hours.

\n" ); document.write( "You can solve any two-part mixture problem like that in the following way.

\n" ); document.write( "All 11 hours at 7mph would cover 77 miles
\n" ); document.write( "All 11 hours at 14mph would cover 154 miles
\n" ); document.write( "The actual distance covered was 119 miles

\n" ); document.write( "Look at the three mileage totals on a number line; with simple calculations, determine that 119 is 42/77 = 6/11 of the way from 77 to 154.
\n" ); document.write( "That means 6/11 of the total time was at the higher rate.
\n" ); document.write( "6/11 of 11 hours is 6 hours.

\n" ); document.write( "ANSWER: 6 hours at 14mph/ 5 hours at 7mph

\n" ); document.write( "CHECK: 6(14)+5(7) = 84+35 = 119

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