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 April 18th, 2014, 06:39 PM #1 Newbie   Joined: Apr 2014 From: San Diego Posts: 1 Thanks: 0 Need Help. Some hardly hikers start on a walk at 2:00 PM and return at 8:00 PM. Their speed is 4 miles per hour on level land, 3 miles per hour uphill, and 6 miles per hour downhill. How many miles was their hike? a) 24 b) 26 c) 28 d) 36
 April 18th, 2014, 10:30 PM #2 Newbie   Joined: Aug 2011 Posts: 17 Thanks: 1 Not sure why this is i the Calculus forum - it is just Distance = Rate times Time. D = RT, so T= D/R. Let A = distance along level round on outgoing portion of the hike the time for this part of the hike = A/4 B = uphill distance of outgoing portion and time = B/6 C = downhill distance of outgoing portion and time = C/3 So A also = distance along level round on outgoing portion of the hike time again = A/4 B = downhill distance of outgoing portion, time = B/3 C = uphill distance of outgoing portion, time = C/6 Adding up total time: A/4 + B/6 + C/3 + A/4 + B/3 + C/6 = (A+B+C)/2 = 6 hours. So A+B+C = 12 and the total distance is 2(A+B+C) = 24 miles.
April 18th, 2014, 10:54 PM   #3
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Quote:
 Originally Posted by alstat Not sure why this is i the Calculus forum...
I have moved the thread appropriately.

April 20th, 2014, 09:15 PM   #4
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Quote:
 Originally Posted by alstat Not sure why this is in the Calculus forum - it is just Distance = Rate times Time. D = RT, so T= D/R. Let A = distance along level round on outgoing portion of the hike the time for this part of the hike = A/4 B = uphill distance of outgoing portion and time = B/6 C = downhill distance of outgoing portion and time = C/3 So A also = distance along level round on incoming portion of the hike time again = A/4 B = downhill distance of incoming portion, time = B/3 C = uphill distance of incoming portion, time = C/6 Adding up total time: A/4 + B/6 + C/3 + A/4 + B/3 + C/6 = (A+B+C)/2 = 6 hours. So A+B+C = 12 and the total distance is 2(A+B+C) = 24 miles.
Just fixing some typos!

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