document.write( "Question 1074804: Bill starts riding his bike towards town at a constant rate of 8 mph. Then, 30 minutes later, his wife starts driving on the same path at a constant average of 30 mph. How long will it take her to catch up to Bill?\r
\n" ); document.write( "\n" ); document.write( "This question is from a study packet, that also has the answer shown as\r
\n" ); document.write( "\n" ); document.write( "8(.5)/30-8 = approx. 18 hours = approx. 10.8 mins = approx 10 minutes 48 seconds.\r
\n" ); document.write( "\n" ); document.write( "When I solve the problem that way, I understand the answer. However, based on my understanding of DRT problems, that doesn't seem correct. The way I solve this is using a table\r
\n" ); document.write( "\n" ); document.write( "Persons R T D
\n" ); document.write( "Bill 8mph t 8(t)
\n" ); document.write( "Wife 30mph t-.5 30(t-.5)\r
\n" ); document.write( "\n" ); document.write( "8t=30(t-.5)
\n" ); document.write( "=8t=30t-15
\n" ); document.write( "=-22t=-15
\n" ); document.write( "=-15/-22
\n" ); document.write( "=.68
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #689463 by MathTherapy(10555)\"\" \"About 
You can put this solution on YOUR website!
Bill starts riding his bike towards town at a constant rate of 8 mph. Then, 30 minutes later, his wife starts driving on the same path at a constant average of 30 mph. How long will it take her to catch up to Bill?\r
\n" ); document.write( "\n" ); document.write( "This question is from a study packet, that also has the answer shown as\r
\n" ); document.write( "\n" ); document.write( "8(.5)/30-8 = approx. 18 hours = approx. 10.8 mins = approx 10 minutes 48 seconds.\r
\n" ); document.write( "\n" ); document.write( "When I solve the problem that way, I understand the answer. However, based on my understanding of DRT problems, that doesn't seem correct. The way I solve this is using a table\r
\n" ); document.write( "\n" ); document.write( "Persons R T D
\n" ); document.write( "Bill 8mph t 8(t)
\n" ); document.write( "Wife 30mph t-.5 30(t-.5)\r
\n" ); document.write( "\n" ); document.write( "8t=30(t-.5)
\n" ); document.write( "=8t=30t-15
\n" ); document.write( "=-22t=-15
\n" ); document.write( "=-15/-22
\n" ); document.write( "=.68
\n" ); document.write( "
You can solve it that way with the table. However, you should understand that you named \"t\" as the time Bill takes to get to the \"meeting point.\"\r\n" );
document.write( "This is correct, but the question asks for the time his WIFE took to catch up to Bill. Therefore, you now need to calculate t - .5, which is the\r\n" );
document.write( "time you have for the wife. When you do that, you get: .68 - .5 = .18 of an hour, which when multiplied by 60, gives you about 10.8 minutes,\r\n" );
document.write( "which is the correct answer. \r\n" );
document.write( "\r\n" );
document.write( "To make it less confusing and get straight to the answer, I would suggest that you let the wife's time be \"t.\" That way, when you get \"t,\"\r\n" );
document.write( "you will have your answer. The table would then look like this:\r\n" );
document.write( "\r\n" );
document.write( "Persons     R      T       D\r\n" );
document.write( "Bill        8mph   t+.5   8(t + .5)\r\n" );
document.write( "Wife        30mph  t      30(t)
\n" ); document.write( "
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