SOLUTION: A bus and a matatu start from Nairobi to kisii via narok at the same time marking a distance of 280km .The matatu averages 20km/h faster than the bus and reaches 96minutes earlier.

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Question 1089807: A bus and a matatu start from Nairobi to kisii via narok at the same time marking a distance of 280km .The matatu averages 20km/h faster than the bus and reaches 96minutes earlier.determine speed of the bus
Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
.
Let x be the speed of the bus, in km/h.

Then the speed of matatu (don't know what is it) is (x+20) km/h.


The time for bus is 280%2Fx hours.

That for matatu is 280%2F%28x%2B2%29 hours.


The condition says that


280%2Fx+-+280%2F%28x%2B20%29 = 8%2F5   (8/5 is 96 minutes = 13%2F5 hours).


To solve it, multiply both sides of your equation by 5x*(x+20). You will get


1400(x+20) - 1400x = 8x*(x+20).

Simplify and solve this quadratic equation.

Choose the positive root from the two.

Good luck !.

*** I solved it mentally and got the answers 50 km/h and 70 km/h ***

If you still have questions or want to report your answer, I will be glad to receive it from you.

For it, use the TY form and do not forget to refer to the problem ID number.
It is 1089807, by the way.

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Just learned from Wikipedia about matatu . . .