Answer:
The motorist's average rate in the morning trip was 50 mph and that for the afternoon trip was 25 mph.
Step-by-step explanation:
Let the motorist's average rate in the afternoon = <em>x</em> mph.
It is given that his average rate in the morning was twice his average rate in the afternoon.
Therefore, his average rate in the morning = 2<em>x</em> mph.
Let <em>t</em> be the time taken for the morning trip.
It is given that he spent 5 hours for driving.
So, the time taken by him for the afternoon trip = 5 - <em>t</em>.
Now, using the formumla, ,
the verbal model for the morning trip is:
<em>xt</em> = 75
The verbal model for the afternoon trip is:
5<em>x</em> - <em>xt</em> = 50
Substituting <em>xt</em> = 75, we get,
5<em>x</em> - 75 = 50
5<em>x</em> = 125
<em>x</em> = 25
2<em>x</em> = 50
Hence, his average rate in the morning trip was 50 mph and that for the afternoon trip was 25 mph.