document.write( "Question 877072: Alice leaves her house, driving East at 45 miles per hour.30 minutes later, her husband Dave notices she forgot her cell phone and sets off after her. How fast must Dave travel in order to catch up with Alice 3 hours after he leaves? \n" ); document.write( "
Algebra.Com's Answer #529197 by ankor@dixie-net.com(22740)\"\" \"About 
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Alice leaves her house, driving East at 45 miles per hour.
\n" ); document.write( "30 minutes later, her husband Dave notices she forgot her cell phone and sets off after her.
\n" ); document.write( " How fast must Dave travel in order to catch up with Alice 3 hours after he leaves?
\n" ); document.write( ":
\n" ); document.write( "From the information given we know:
\n" ); document.write( "3.5 hrs is A's travel time
\n" ); document.write( "and
\n" ); document.write( "3 hrs is Dave's travel time
\n" ); document.write( ":
\n" ); document.write( "let s = speed required for D to catch A
\n" ); document.write( ":
\n" ); document.write( "When D catches A, they will have traveled the same distance
\n" ); document.write( "Write a dist equation; dist = speed * time
\n" ); document.write( "3s = 3.5(45)
\n" ); document.write( "3s = 157.5
\n" ); document.write( "s = 157.5/3
\n" ); document.write( "s = 52.5 mph to catch A in 3 hrs
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\n" ); document.write( ":
\n" ); document.write( "Check this by finding the distance each traveled
\n" ); document.write( "3 * 52.5 = 157.5
\n" ); document.write( "3.5 * 45 = 157.5 mi \n" ); document.write( "
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