There are 6 boxes numbered 1, 2,...6. Each box is to be filled up either with a red or a green ball in such a way that at least 1 box contains a green ball and the boxes containing green balls are consecutively numbered. The total number of ways in which this can be done is	Choose the correct answer:
A) 5 B) 21 C) 33 D) 60 E) 40
Given the constraints of this question, we have to consider 6 possible outcomes...   1 green ball: 6 options   GRRRRR   RGRRRR   RRGRRR   RRRGRR   RRRRGR   RRRRRG   2 green balls: 5 options   GGRRRR   RGGRRR   RRGGRR   RRRGGR   RRRRGG   3 green balls: 4 options   GGGRRR   RGGGRR   RRGGGR   RRRGGG   4 green balls: 3 options   GGGGRR   RGGGGR   RRGGGG   5 green balls: 2 options   GGGGGR   RGGGGG   6 green balls: 1 option   GGGGGG    6+5+4+3+2+1= 
<gadget id="calculator"> 6+5+4+3+2+1</gadget>
<output>21</output>
21 options.   21
<result>B</result>
There are 6 boxes numbered 1, 2,...6. Each box is to be filled up either with a red or a green ball in such a way that at least 1 box contains a green ball and the boxes containing green balls are consecutively numbered. The total number of ways in which this can be done is