SOLUTION: Alexa makes a journey of 430km, traveling 160km by bus and 270km by car. If the car
averages 10km/h faster than the bus and the whole journey takes 5 hours, what is the
speed of
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-> SOLUTION: Alexa makes a journey of 430km, traveling 160km by bus and 270km by car. If the car
averages 10km/h faster than the bus and the whole journey takes 5 hours, what is the
speed of
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Question 1155618: Alexa makes a journey of 430km, traveling 160km by bus and 270km by car. If the car
averages 10km/h faster than the bus and the whole journey takes 5 hours, what is the
speed of the car? Found 3 solutions by ikleyn, mananth, MathTherapy:Answer by ikleyn(52814) (Show Source):
Write the "time equation"
+ = 5 hours,
where x is the unknown speed of the car.
And then solve it.
ANSWER (which can be obtained mentally) is x= 90 kilometers per hour.
You can put this solution on YOUR website! Alexa makes a journey of 430km, traveling 160km by bus and 270km by car. If the car
averages 10km/h faster than the bus and the whole journey takes 5 hours, what is the
Time by bus + time by car = 5
Multiply by LCD
160 (x + 10 )+ 270 x = 5 x(x+ 10 )
160 x + 1600 ,+ 270 * x = 5 x^2 + 50
-5 X^2+ 380 x + 1600 = 0
Find the roots of the equation by quadratic formula
You can put this solution on YOUR website! Alexa makes a journey of 430km, traveling 160km by bus and 270km by car. If the car
averages 10km/h faster than the bus and the whole journey takes 5 hours, what is the
speed of the car?
Once again, this can be done MUCH, MUCH simpler! No need to use the quadratic equation formula!
Let the car's speed be S
Then the bus' speed = S - 10
We then get the following TIME equation: ------ Factoring out GCF, 5, in numerator
32S + 54(S - 10) = S(S - 10) -------- Multiplying by LCD, S(S - 10)
(S - 90)(S - 6) = 0
S, or speed of car = OR S = 6 (ignore)
