<PRE><B>Question 891626</B>
A car travels 30 kph faster than a truck . The car covers 540 km in three hours less than the time it takes to travel the same distance how fast does the car travel?
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let x=speed of truck
x+30=speed of car
{{{540/x-540/(x+30)=3}}}
lcd:x(x+30)
540(x+30)-540x=3x(x+30)
540x+16200-540x=3x^2+90x
3x^2+90x-16200=0
x^2+30x-5400=0
(x+90)(x-60)=0
x=-90 (reject)
or
x=60
x+30=90
how fast does the car travel? 90 km/hr</PRE>