Dennis rollerblades 100 yards per minute while gina rollerblades 85 yards per minute, if they start out skating together, how many yards ahead will dennis be after one hour?

100*60(60minute=1hr)= 6000

85*60= 5100

subtract 5100 from 6000= 900

Dennis would be at 900 yard in an hour

Not the answer but here is the graph. 

Which of the following is an example of an opposing signal? no examplthates given.   i would say, that traffic lights in a city at major intersections direct the flow of traffic in opposite directions so would be an example.also, stop signs on either side of the same street would be an example. at a train crossing, the light for allowing car traffic in opposite directions or not would be another example.