Answer:
1/6
Explanation:
This is conditional probability.
If heads is tossed, then and only then does he have the option to draw either green or red and have the full 'Head, Green/Red' combination.
So, the probability of the first event - getting heads, is 1/2, since either heads or tails can be flipped with 50/50 chance.
The probability of the second event - picking either green or red, is 1/3, since there are 6 colour options - blue, red, yellow, green, orange and purple - of which 2 can be chosen. Thus, 2/6, which simplifies to 1/3
Now since these are both independent events, we must multiply their probabilities.
1/3 * 1/2 = 1/6