Question 1150653
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The average rate is the total distance divided by the total time.


Total time is  {{{24/16}}} + {{{20/12}}} = {{{(3*24)/48}}} + {{{(4*20)/48}}} = {{{(72+80)/48}}} = {{{152/48}}} = {{{19/6}}}  hours.


The average rate = {{{(24+20)/((19/6))}}} = {{{44/((19/6))}}} = {{{(44*6)/19}}} = {{{264/19}}} = {{{13}}}{{{17/19}}}  miles per hour.
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Very ugly numbers; &nbsp;I don't know who created this problems, &nbsp;which excellent educational ideas 
does he (or she) keep in his mind and what you can learn making such calculations.