Two heavily loaded sixteen-wheeler transport trucks are 690 kilometers apart, sitting at two rest stops on opposite sides of the same highway. Driver A begins heading down the highway driving at an average speed of 90 kilometers per hour. Exactly one hour later, Driver B starts down the highway toward Driver A, maintaining an average speed of 80 kilometers per hour. How many kilometers farther than Driver B, will Driver A have driven when they meet and pass each other on the highway?  Choose the correct choice from the following options:	A) 120	B) 130	C) 150	D) 320	E) 450
I've been reading the website for a while and I'm always keen to see different approaches so I would like to share one that works for me:   Short version:   Truck A travels for an hour.   Distance remaining = 690-90= 
<gadget id="calculator">690-90</gadget>
<output>600</output>
600k   Ratio of speeds 9:8 -&gt; 510/17= 30   Truck 120 = 90 + 30*9= 
<gadget id="calculator">90 + 30*9</gadget>
<output>360</output>
360   Truck B= 30*8= 
<gadget id="calculator">30*8</gadget>
<output>240</output>
240   Delta= 120km   120nswer 120
<result>A</result>
Two heavily loaded sixteen-wheeler transport trucks are 690 kilometers apart, sitting at two rest stops on opposite sides of the same highway. Driver A begins heading down the highway driving at an average speed of 90 kilometers per hour. Exactly one hour later, Driver B starts down the highway toward Driver A, maintaining an average speed of 80 kilometers per hour. How many kilometers farther than Driver B, will Driver A have driven when they meet and pass each other on the highway?