SOLUTION: In a bicycle race over a 20 km route, Danny finished 8 minutes ahead of John. Danny pedaled 5 km per hour faster than John. What was Danny's rate
Question 833439: In a bicycle race over a 20 km route, Danny finished 8 minutes ahead of John. Danny pedaled 5 km per hour faster than John. What was Danny's rate Found 2 solutions by josgarithmetic, MathTherapy:Answer by josgarithmetic(39625) (Show Source): You can put this solution on YOUR website! Uniform rates for travel, using .
This example is in kilometers and hours.
8 minutes is hour
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Let t = time for John to finish the race
A rate*time=distance equation can be made for each of Danny and John.
John: , which can also be used as
Danny:
Substituting with John's equation,
Multiply members by 15 to clear the denominators
Make use of John's equation: ----Quadratic equation in r, the rate for John.
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Use the * general solution to a quadratic equation to solve for r, even through the question really just asks for Danny's rate; both rates are given a relationship in the description.
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* The quadratic expression on the left hand side is factorable, so you might be able to explore the factorizations of 750, but you will find that the equation is .
The meaningful answer is, . This means, Danny's rate was 35 kilometers per hour. Answer by MathTherapy(10555) (Show Source): You can put this solution on YOUR website!
In a bicycle race over a 20 km route, Danny finished 8 minutes ahead of John. Danny pedaled 5 km per hour faster than John. What was Danny's rate
Danny's speed: km/h
You can do the check!!
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