SOLUTION: Erin rides her bike from home to school in 15 minutes. If she increases her speed by 5 km/hr, she reduces her travel time by 5 minutes. What is the distance from her home to her

Question 1085265: Erin rides her bike from home to school in 15 minutes. If she increases her speed by 5 km/hr, she reduces her travel time by 5 minutes. What is the distance from her home to her school.
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = the distance from home to school in km
Let = her speed in km/hr
Let =her time in hrs to go from home to school
-------------------------------------------------

Convert minutes to hrs
[ min ] x [ hrs/min ] = [ hrs ]
hrs
and, also:
hrs
----------------------------
Her equation for a normal trip is:
(1)
If she increases her speed, the equation is:
(2)
----------------------------------
(2)
(2)
Plug (1) into (2)
(2)
Multiply both sides by
(2)
(2) km/hr
and
(1)
(1)
(1) km
The distance from home to school is 2.5 km
--------------------------------------------
check answer:
(2)
(2)
(2)
(2)
(2) km
OK

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