ross Posted November 24, 2008 Report Share Posted November 24, 2008 i'm horrible with word problems and this is a take home quiz of 4 questions worth 100 points and i'm stuck on a problem.heres the problem:Mark's workout consists of jogging for 3 miles, and then riding his bike for 5 miles at a speed 4 miles per hour faster than he jogs. If his total workout time is 1 hour, find his jogging speed and his biking speed. Quote Link to comment Share on other sites More sharing options...
John Posted November 24, 2008 Report Share Posted November 24, 2008 i think its 6 and 10.jog 3 miles at 6 mph = 30 minutesbike 5 miles at 10 mph = 30 minutesthat seems to fit everything. 60 minute workout, and bike speed is 4mph faster than running speed. Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 haha thanks man i just got the same answer..now i just need to figure out how to show the work because i didn't figure it out "by the book" in the way the professor wants to see the work Quote Link to comment Share on other sites More sharing options...
John Posted November 24, 2008 Report Share Posted November 24, 2008 running speed = xbike speed = x+4runs 3 miles/.5 hour = 6 mph6mph + 4 mph= 10 mphbikes 5 miles/.5 hour = 10 mph ??? Quote Link to comment Share on other sites More sharing options...
Kip Drordy Posted November 24, 2008 Report Share Posted November 24, 2008 i'm horrible with word problems and this is a take home quiz of 4 questions worth 100 points and i'm stuck on a problem.heres the problem:Mark's workout consists of jogging for 3 miles, and then riding his bike for 5 miles at a speed 4 miles per hour faster than he jogs. If his total workout time is 1 hour, find his jogging speed and his biking speed.Are you still in elementary school? Quote Link to comment Share on other sites More sharing options...
John Posted November 24, 2008 Report Share Posted November 24, 2008 not everyone is an asian math genius. Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 Are you still in elementary school?haha no...math 104 at columbus state. its intermediate algebra. Quote Link to comment Share on other sites More sharing options...
BornSinner Posted November 24, 2008 Report Share Posted November 24, 2008 not everyone is an asian math genius.DAMN!!!!You beat me to it Quote Link to comment Share on other sites More sharing options...
John Posted November 24, 2008 Report Share Posted November 24, 2008 you could write it like this maybe, where x is jogging and Y is bikingx mph * .5 hour = 3 milesx = 3/.5x = 6------y = (x+4)y mph * .5 hour = 5 milesy = 5/.5y = 10 Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 the only issue i see is how do i prove that it takes .5 hr for each exercise? in the original problem it only says the total workout lasts 1 hr. Quote Link to comment Share on other sites More sharing options...
Kip Drordy Posted November 24, 2008 Report Share Posted November 24, 2008 You don'tRunning speed = xBiking speed = x+4x = miles/minTime (60 min) = 3/x + 5/(x+4) Quote Link to comment Share on other sites More sharing options...
yotaman88210 Posted November 24, 2008 Report Share Posted November 24, 2008 You don'tRunning speed = xBiking speed = x+4x = miles/minTime (60 min) = 3/x + 5/(x+4) Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 i fucking hate math Quote Link to comment Share on other sites More sharing options...
Kip Drordy Posted November 24, 2008 Report Share Posted November 24, 2008 i fucking hate mathYea, but it's like anything else, the more you practice the better you'll get. Did you solve it? I could give you the rest of the solution, but you'll be better off trying to figure it out yourself first.Besides this is the kind of shit that you might have to use one day. Motor sports in general is very math intensive. Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 i tried to work it out to solve for x using the equation you gave me..Time (60 min) = 3/x + 5/(x+4)then i used the LCD to get the x out of the denominator but i messed it up somehow...i'm just getting frustrated with a problem that should be easy as pi(no pun intended). Quote Link to comment Share on other sites More sharing options...
John Posted November 24, 2008 Report Share Posted November 24, 2008 Imo it should be1 = 3/x + 5/(x+4)Not 60 =Because we are dealing with Miles per hour not miles per minute Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 Imo it should be1 = 3/x + 5/(x+4)Not 60 =Because we are dealing with Miles per hour not miles per minutemy thoughts exactly but i tried the problem both ways anyway Quote Link to comment Share on other sites More sharing options...
Kip Drordy Posted November 24, 2008 Report Share Posted November 24, 2008 Actually it would have been easier to use 1 hour instead of 60 min. (hint hint quadratic) Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 so if i take the equation 1=3/x + 5/(x+4) and move 3/x to the other side, then cross multiply i get the answer of x=6...only problem i see now is that when i move 3/x to the other side, it should become -3/x and then the equation doesn't result in x=6 Quote Link to comment Share on other sites More sharing options...
Kip Drordy Posted November 24, 2008 Report Share Posted November 24, 2008 here we go:1=3/x + 5/(x+4)cross multiply 3/x and 5/(x+4) to then add fractionsyou should end up with: 1 = (3x + 5x + 12) / x^2 + 4xmove the right side of the equation to the left and set to 0: x^2 + 4x - 3x - 5x - 12 = 0add like terms:x^2 - 4x -12 = 0Plug and chug in the quadratic equation and you'll get values of -2 and 6Since you can't travel at a negative speed 6 is your answer. Quote Link to comment Share on other sites More sharing options...
ross Posted November 24, 2008 Author Report Share Posted November 24, 2008 here we go:1=3/x + 5/(x+4)cross multiply 3/x and 5/(x+4) to then add fractionsyou should end up with: 1 = (3x + 5x + 12) / x^2 + 4xmove the right side of the equation to the left and set to 0: x^2 + 4x - 3x - 5x - 12 = 0add like terms:x^2 - 4x -12 = 0Plug and chug in the quadratic equation and you'll get values of -2 and 6Since you can't travel at a negative speed 6 is your answer.sweet..thanks man i couldn't get it through my head how to set it up as a quadratic. Quote Link to comment Share on other sites More sharing options...
BornSinner Posted November 24, 2008 Report Share Posted November 24, 2008 it's all good manLet me know if you need any other help Quote Link to comment Share on other sites More sharing options...
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