document.write( "Question 1001955: Tobias starts out jogging from Dauntless Headquarters at 6:00 a.m. at a speed of 4 mi/h. Twelve minutes later, Tris starts out from Dauntless Headquarters and follows the same route. At what constant rate in miles per hour must Tris run to catch Tobias at 6:42 a.m.? Put answer into nearest tenth decimal \n" ); document.write( "

Algebra.Com's Answer #618985 by josgarithmetic(39618) $\"\"$ $\"About$

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RT=D; use time quantities instead of points on a time line; set up a data table for rates, times, distances. \"Catch-up\" is when Tobias and Tris went the same distance. Best unit for time will be in the equivalents as HOURS.\r
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\n" ); document.write( "\"~yes\".\r
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\n" ); document.write( "\n" ); document.write( "Time QUANTITIES are used here in unit of HOURS or fractions of hours.
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document.write( "              rate         time in hours     distance\r\n" );
document.write( "Tobias         4           t+12/60            d\r\n" );
document.write( "Tris           r            42/60-12/60       d\r\n" );
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\n" ); document.write( "The description is enough information to obtain two equations, but the system will have THREE unknown variables of r, t, and d.\r
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\n" ); document.write( "\n" ); document.write( "--After some thought, t=42/60-12/60 and time becomes a knowable constant for Tobias and another for Tris; making t as known. Make this adjustment and the only unknowns are r and d. \n" ); document.write( "

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