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Two trains travel directly toward each other. One of the trains travels at a rate of 12 km/h while the other travels at a rate of 20 km/h. When the trains are 72 km apart, a conductor at the front of one of the trains releases the insane pigeon Hyde. Hyde flies first from the slower of the two trains to the faster train at which point Hyde doubles back toward the slower train. Hyde continues to fly back and forth between the trains as they approach, always at a constant speed of 48 km/h. Assuming the trains never change speed until they meet and magically stop, how many kilometers has Hyde flown when the trains meet?

 Jun 18, 2019
 #1
avatar+128089 
+2

Note that every hour...the trains close the distance between them by  [ 12 + 20 ]  = 32 km

 

So.....the time until they meet  =   72  / 32  =   18 / 8   =   9 /4   hrs

 

Since "Hyde"  flies constantly  during this time....the distance he covers is 

 

Rate * Time  = Distance 

 

48 * (9/4)  =

 

(48/4) * 9  =

 

12 * 9  =

 

108 km

 

CORRECTED....!!!!

 

cool cool cool

 Jun 18, 2019
edited by CPhill  Jun 18, 2019
edited by CPhill  Jun 18, 2019
 #2
avatar+209 
-2

THX CPHILL but the answer says your wrong... And its not showing me the solution

NoobGuest  Jun 18, 2019
edited by NoobGuest  Jun 18, 2019
 #3
avatar+128089 
0

Math error

 

12 * 9  =   108 km!!!

 

cool cool cool

CPhill  Jun 18, 2019
edited by CPhill  Jun 18, 2019
 #4
avatar+209 
-1

THANK YOU

NoobGuest  Jun 18, 2019
 #5
avatar+209 
-1

and your right!

NoobGuest  Jun 18, 2019

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