Question

a ship can cover A certain distance in 10 hours at a speed of 16 miles per hour how much should its speed be increased so that it takes only 8 hours to cover the same distance

Answer 1

A ship can cover a certain distance in 10 hours at a speed of 16 nautical miles per hour. By how much should its speed be increased so that it takes only 8 hours to cover the same distance? 
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d = r*t = 16*10 = 160 nm
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t = d/r
8 = 160/r
r = 20 knots
An increase of 4 knots.
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1 knot = 1 nm/hr 
Answer by stanbon(75803)   (Show Source): You can put this solution on YOUR website!
A ship can cover a certain distance in 10 hours at a speed of 16 nautical miles per hour. By how much should its speed be increased so that it takes only 8 hours to cover the same distance? (A nautical mile in a unit of measurement used at sea distance or sea water i.e. 1852 metres)
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Original DATA:
time = 10 hrs ; rate = 16 nmh ; distance = 10*16 = 160 km
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New DATA:
time = 8 hrs ; rate = 16+x nmh ; distance = 128 + 8x km
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Equation:
distance = distance
160 km = 128+8x km
32 = 8x
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Ans: x = 4 kmh (amt. speed must increase)

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