At first tourists 84 kilometers floated 2 hours 20 minutes by motor ship on the lake, and then 89.6 kilometers down the river against the current and came back the same route. Find, the travel there and back what is the time continued if the speed of a watercourse 2.4 kmchas.

350
Answer: 9 hours 40 minut2 the h 20 min. =2 1/3 h 1) 84:2 1/3=36 (km/h) - the speed of ship 2) 89.6: (36-2.4) =2 2/3(ch) - 3 went against the stream) 89.6: (36+2.4) =2 1/3(ch) - on a current 4) 2 2/3+2 1/3+2*2 1/3=9 2/3 h =9 h 40 min. - vputa time
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