<PRE><B>Question 778233</B>
Sam and Rachel leave a park at the same time and ride home. Sam rides at 15 km/h and Rachel rides at 11 km/h. Sam gets home 12 minutes before Rachel. How long did it take Sam to ride home from the park?

let Sam take t hours
Sam rate = 15 km/h

Rachel takes t+12 minutes = t+1/5 hours
Rachel rate = 11 km/h

Distance is the same 

distance Rachel = distance Sam
d=rt
15t=11(t+(1/5))

15t=11((5t+1)/5)

multiply by 5

75t=11(5t+1)

75t=55t+11

20t=11
t=11/20 hours

11/20 * 60 = 33 minutes

Sam took 33 minutes








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