a motorboat whose speed is 18 km per hour in still water takes 1 hour more to go 24 km upstream then to return downstream to the same spot find the speed of the stream
Answers
Answer:
6km/Hr
Step-by-step explanation:
a motorboat whose speed is 18 km per hour in still water takes 1 hour more to go 24 km upstream then to return downstream to the same spot find the speed of the stream
Speed of MotorBoat = 18 km/hr
Let say speed of stream = S km/Hr
Down Stream speed = 18 + S km/Hr
Upstream Speed = 18 - S km/Hr
Distance each side = 24 km
Time taken for upstream = 24/(18 -S) hr
Time Taken for Downstream = 24/(18 + S) hr
Time taken for upstream is 1 hr more than downstream
24/(18-S) - 24/(18+S) = 1
Multiplying both sides by (18-S)(18+S)
=> 24 (18 + S) - 24(18-S) = (18-S)(18+S)
=> 24 ( 2S) = 324 - S²
=> S² + 48S - 324 = 0
=> S² + 54S - 6S - 324 = 0
=> S(S+54) - 6(S+54) = 0
=> (S-6) (S +54) = 0
=> S = 6 ( S can not be - ve)
Speed of stream = 6 km/Hr
this is your answer hope it will help you
