One hour after Yolanda started walking from X to Y, a distance of 52 miles, Bob started walking along the same road from Y to X. If Yolanda's walking rate was 3 miles per hour and Bobт's was 4 miles per hour, how many miles had Bob walked when they met? Choose the correct choice:	A) 28	B) 23	C) 22	D) 21	E) 19.5
When B started walking Y already has covered 3 miles out of 52, hence the distance at that time between them was   52-3= 
<gadget id="calculator">  52-3</gadget>
<output>49</output>
49 miles.   Combined rate of B and Y was   3+4= 
<gadget id="calculator">  3+4</gadget>
<output>7</output>
7 miles per hour, hence they would meet each other in  49/7= 
<gadget id="calculator"> 49/7</gadget>
<output>7</output>
7 hours. In 6 hours B walked  7*4= 
<gadget id="calculator"> 7*4</gadget>
<output>28</output>
28 miles.   28nswer: 28.
<result>A</result>
One hour after Yolanda started walking from X to Y, a distance of 52 miles, Bob started walking along the same road from Y to X. If Yolanda's walking rate was 3 miles per hour and Bobт's was 4 miles per hour, how many miles had Bob walked when they met?