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Word equation:Two buses were coming from two different places situated just in the...

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spsaroj | Student, Grade 10 | Honors

Posted June 28, 2012 at 2:01 PM via web

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Word equation:

Two buses were coming from two different places situated just in the opposite direction. The average speed of one bus is 5 km/hr more than that of another one and they had started their journey in the same time. If the distance between the places is 500 km and they meet after 4 hours, find their speed.

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htorrino | eNotes Newbie

Posted June 28, 2012 at 4:10 PM (Answer #1)

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To start, you have represent the rate of each bus.

Let x = rate of the first bus and x + 5 = rate of the 2nd bus.

Note that distance = rate*time and t = 4. The distance they traveled in 4 hours was equal to 500. So the working equation should be:

x*4 + (x + 5)*4 = 500

4x + 4x + 20 = 500

8x + 20 = 500   subtracting 20 from both sides

     8x = 480   divide both sides by 8

       x = 60 kph

   x + 5 = 65 kph

 

The speed of the buses are 60 kph and 65 kph.

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vaaruni | High School Teacher | Salutatorian

Posted June 30, 2012 at 6:26 AM (Answer #2)

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given : the distance between the two places from where the buses start = 500 km, The time after whuch they meet each other = 4hr. and the Avg. speed of one bus is 5 km/hr more Than the other bus.

Let the bus A start from a place P and the bus B start from the place Q and let they meet at a point R after the journey of  4hr.                      the distane PQ = 500 km.                   

Let the avg. speed of the bus A = x km/hr the the avg. speed of the second bus B= (x + 5)km/hr.

The distance travelled by the bus A in 4hr. = PR = 4x                         The distance travelled by the bus B in 4hr. = QR = 4(x + 5)

       PR + QR = PQ

       4x + 4(x + 5) = 500

Or,   4x + 4x + 20 = 500

Or,    8x = 500 - 20 

Or,    8x = 480

Or,    x = 480/8 = 60

Therefore  x = 60 km/hr   and  x + 5 = 60 + 5 = 65 

Hence The average speed ot the two buser are :                                60km/hr and 65km/hr  

 

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