Fred and Sam are standing 40 miles apart and they start walking in a straight line toward each other at the same time. If Fred walks at a constant speed of 4 miles per hour and Sam walks at a constant speed of 4 miles per hour, how many miles has Sam walked when they meet?  Answers.
A) 5 B) 9 C) 20 D) 30 E) 45
relative distance =40 miles   relative speed =4+4= 
<gadget id="calculator">4+4</gadget>
<output>8</output>
8 miles per hour   time taken=40/8= 
<gadget id="calculator">40/8</gadget>
<output>5</output>
5 hours   distance travelled by sam=4*5= 
<gadget id="calculator">4*5</gadget>
<output>20</output>
20 miles=20
<result>C</result>
Fred and Sam are standing 40 miles apart and they start walking in a straight line toward each other at the same time. If Fred walks at a constant speed of 4 miles per hour and Sam walks at a constant speed of 4 miles per hour, how many miles has Sam walked when they meet?