amen!!!
try to picture both yolanda and bob in oppsoite sides of a road.... they are walking at different rates towards each other (45m).
it says that yolanda walked for an hour. her rate is 3mph, therefore she walked 3m, so thye are 42miles apart.
now bob starts walking at 4mph, and yolnada si already walking 3mph. the rule for combined rate is that when objects are moving toward each other you add both rate. but if you didn't know that, try to picture them walking each hour towards each other.
so after the 2nd hour, yolanda walked 6mp (3*2) and bob 4 miles, they are still 35m apart.... continue this logic and u'll see that after 6hours they meet each other.
