Every disk in a bag is either blue, yellow or green. The ratio of blue disks to yellow disks to green disks in this bag is 3 : 7 : 8. If the total number of disks in the bag is 126, how many more green disks than blue disks are in the bag? Select the correct option:
A) 25
B) 28
C) 30
D) 35
E) 40
Let B:Y:G = 3x:7x:8x.   3x + 7x + 8x = 18x 3  + 7  + 8= 
<gadget id="calculator">3  + 7  + 8</gadget>
<output>18</output>
18x= 126 --&gt; x= 7.   G - B = 8x - 3x = 5x 8  - 3= 
<gadget id="calculator">8  - 3</gadget>
<output>5</output>
5x= 35.   The answer is 35.
<result>D</result>
Every disk in a bag is either blue, yellow or green. The ratio of blue disks to yellow disks to green disks in this bag is 3 : 7 : 8. If the total number of disks in the bag is 126, how many more green disks than blue disks are in the bag?