document.write( "Question 637714: An ambulance left the hospital and drove south. 3 hours later a police car left driving 42 k/h faster attempting to catch up to the ambulance. The officer caught up after 2 hours. Find the average speed of the ambulance. \n" ); document.write( "
Algebra.Com's Answer #401869 by ankor@dixie-net.com(22740)\"\" \"About 
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An ambulance left the hospital and drove south.
\n" ); document.write( " 3 hours later a police car left driving 42 k/h faster attempting to catch up to the ambulance.
\n" ); document.write( " The officer caught up after 2 hours. Find the average speed of the ambulance.
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\n" ); document.write( "Let a = the speed of the ambulance
\n" ); document.write( "then
\n" ); document.write( "(a+42) = the speed of the police car
\n" ); document.write( ":
\n" ); document.write( "From the information given, we know the travel time of the ambulance = 5 hrs
\n" ); document.write( "and the Cop = 2 hrs
\n" ); document.write( ":
\n" ); document.write( "When the cop catches the amb, they will have traveled the same distance
\n" ); document.write( "Write a distance equation
\n" ); document.write( "dist = speed * time
\n" ); document.write( ":
\n" ); document.write( "5a = 2(a+42)
\n" ); document.write( "5a = 2a + 84
\n" ); document.write( "5a - 2a = 84
\n" ); document.write( "3a = 84
\n" ); document.write( "a = 84/3
\n" ); document.write( "a = 28 mph speed of the ambulance
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Confirm this by finding the distances, should be equal
\n" ); document.write( "5(28) = 140 km
\n" ); document.write( "2(28+42) = 140 km \n" ); document.write( "
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