Q:

Tom and Linda stand at point A. Linda begins to walk in a straight line away from Tom at a constant rate of 2 miles per hour. One hour later, Tom begins to jog in a straight line in the exact opposite direction at a constant rate of 6 miles per hour. If both Tom and Linda travel indefinitely, what is the positive difference, in minutes, between the amount of time it takes Tom to cover the exact distance that Linda has covered and the amount of time it takes Tom to cover twice the distance that Linda has covered?A. 60B. 72C. 84D. 90E. 108

Accepted Solution

A:
Answer:Then 1/2 or  30 minutes is the required time for Tom to cover the exact distance that Linda one hour before.Two hours after Tom began Tom would cover 12 miles and three hours after Linda started Linda would be 6 miles far away from the starting pointStep-by-step explanation:Linda walks in a straight line at 2 miles/hourthen after t ( hours time) she is    2 (m/h) * t   = d (L)for Tom running at 6 m/h starting one hour later to cover the same distance d(L)d(L)  =  6 m/h * ( t - 1 )    then: 2 (m/h) * t   =   6 m/h * ( t - 1 ) 2*t  =  6*t - 64*t = 6t = 6/4t =  1,5 hChecking that result.we see that in 1,5 hours Linda has covered  2* 1,5  = 3 milesand  in 0.5 hours  Tom covered the same distance  0,5 * 6 = 3 milesNOTE: Remember that tom started one hour later.Then 1/2 or  30 minutes is the required time for Tom to cover the exact distance that Linda one hour before.b)  In this cased(T) = 6* ( t - 1 )       must be equal  to  twice of the Linda distanced(L)  = 2 * 2 * t6*t - 6  =  4*t2*t  =  6t  = 3To check itin 3 hours   Linda had covered  3 * 2  =  6 milesin 2 hours   Tom had covered   2 * 6  =  12 miles