SOLUTION: you and your friend live 12 miles apart. you leave home at the same time and travel towards eachother. you walk at a rate of 4 miles per hours and your bicycles at a rate of 11 mil

Algebra ->  Expressions-with-variables -> SOLUTION: you and your friend live 12 miles apart. you leave home at the same time and travel towards eachother. you walk at a rate of 4 miles per hours and your bicycles at a rate of 11 mil      Log On


   

Question 1045424: you and your friend live 12 miles apart. you leave home at the same time and travel towards eachother. you walk at a rate of 4 miles per hours and your bicycles at a rate of 11 miles per hour. how long after you leave home will you meet?how far from home will each of you be?
suppose your friend bikes at a rate of 12 miles per hour how much sooner will you meet? how far from home will each of you be?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
RT=D is Travel Rates Rule for constant rate R. 
                  RATE      TIME       DISTANCE
PERSON            r%5Bp%5D      t
FRIEND            r%5Bf%5D      t
TOTAL                                    d

"PERSON" is referenced as traveling or traveled "from home". The number for this will be r%5Bp%5D%2At. 

                  RATE      TIME       DISTANCE
PERSON            r%5Bp%5D      t          r%5Bp%5D%2At
FRIEND            r%5Bf%5D      t          r%5Bf%5D%2At
TOTAL                                    d

Description established

r%5Bp%5Dt%2Br%5Bf%5Dt=d
t%28r%5Bp%5D%2Br%5Bf%5D%29=d
highlight%28t=d%2F%28r%5Bp%5D%2Br%5Bf%5D%29%29


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Practical thinking is to use that both people starting at same time going toward each other decrease in distance at the SUM of their two rates. Calling this sum S, travel time t, known distance D, you can simply have S%2At=D and then t=D%2FS.
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What this means for the first part of the example is time is 12%2F%284%2B11%29 hours, or 12%2F15=%283%2A4%29%2F%283%2A5%29=highlight%28%284%2F5%29hour=48%2Aminutes%29.