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A motorboat whose speed in still water is 18 km/h, takes 1 hour more to go 24 km upstreamthan to return downstream to the same spot. Find the speed of the stream. |
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Answer» Answer: s=6km/hr Step-by-step EXPLANATION: Given: Speed of BOAT in STILL water = 18km/hr Let speed of the stream = s Speed of boat upstream = Speed of boat in still water - speed of stream = 18−s Speed of boat down stream = Speed of boat in still water + speed of stream = 18+s Time TAKEN for upstream = Time taken to cover DOWNSTREAM + 1 24(18+s)=24(18−s)+(18−s)(18+s) ⇒s 2 +48s−324=0 ⇒s 2 +54s−6s−324=0 ⇒(s+54)(s−6)=0 ⇒s=6,−54 ⇒s =−54 Thus, s=6km/hr, Speed of steam cannot be negative. |
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