document.write( "Question 1015582: if the speed limit is decreased by 10 km/h on a 100 km stretch of a highway, the trip will take a half hour longer than usual. what is the usual speed limit \n" ); document.write( "

Algebra.Com's Answer #631954 by MathTherapy(10556) $\"\"$ $\"About$

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if the speed limit is decreased by 10 km/h on a 100 km stretch of a highway, the trip will take a half hour longer than usual. what is the usual speed limit
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Let usual speed limit be S
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document.write( "Then time taken at usual speed = 
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document.write( "Decreasing the speed makes the new speed, S – 10
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document.write( "Time taken at new speed: 
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document.write( "We then get:  
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document.write( "100(2)(S – 10) = 100(2S) – S(S – 10) ------- Multiplying by LCD, 2S(S – 10) 
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document.write( "(S - 50)(S + 40) = 0
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document.write( "S, or original speed limit =  \n" );
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