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A raft was sent away from point A downstream. A patrol-boat left A 5 hour and 20 min later and caught up with the raft 20 km away from point A. What was the speed of the raft if the speed of the patrol-boat was 12 km/hour?

solve using a system of equations. will mark brainliest for correct answer and working

Respuesta :

mhanifa

Answer:

  • 2 6/7 km/h

Step-by-step explanation:

t - time spent by boat, s - speed of the raft

time  = distance / speed

Equations:

  • t = 20 / 12
  • t + 5 h 20 m = 20 / s

Time the patrol-boat spent:

  • t = 20/12 = 5/3 h

Time the raft spent:

  • 5 h 20 min + t =
  • 5 1/3  + 5/3 =
  • 16/3 + 5/3 =
  • 21/3 =
  • 7 hours

The speed of the raft:

  • 7 = 20/s
  • s = 20/7
  • s = 2 6/7 km/h

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