Question 1203725
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Please help me with this two questions.
1. A lorry has a velocity of 90 km/h. How far does the lorry travel in 3/4 minutes?
2. A motorist travel's from town A to B, 145 km in 3hrs 45 minutes. Find it's average speed?
Please I would like to get the solving to the questions in case of next time. Thank you.
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<pre>
(1)  As you know,  1 hour is 60 minutes.

     Hence, 1 minute = {{{1/60}}} of an hour.

     Next, 3/4 of a minute is  {{{(3/4)*(1/60)}}} of an hour = {{{(1/4)*(1/20)}}} = {{{1/80}}} of an hour.

     Finally, the distance is the product of the speed by the time, or, in this problem,

         {{{90*(1/80)}}} = {{{9/8}}} kilometers, in problem (1).


     <U>ANSWER</U>.  In 3/4 minutes, the lorry travels  {{{9/8}}} kilometers.



(2)  We want to express the speed of the motorist in kilometers per hour.

     THEREFORE, we convert 3 hours 45 minutes to hours:

                3 hours 45 minutes = 3{{{3/4}}}  hours = {{{(12+3)/4}}} hours = {{{15/4}}} hours.


     Next, the speed is the distance divided by the time.  
     So, in this problem the speed is

         {{{145/((15/4))}}} = {{{(145*4)/15}}} = reduce fraction = {{{(29*4)/3}}} = {{{116/3}}} = 38{{{2/3}}} kilometers per hour.


     <U>ANSWER</U>.  In this problem, the speed is 38{{{2/3}}} kilometers per hour.
</pre>

Solved, with explanations.