Is that the full question or does it say like a certain percent of $12.90 was color or?
Check the picture below.
notice, it simply got mirrored over the vertical y-axis.
Answer:
where
is the amount of banners sold.
Step-by-step explanation:
We know the team has already spent $40, and they earn #3.5 per banner.
Hence, with
representing the amount of banners sold, the equation is 
Let the boy be B and the girl be G
there are six possible outcomes
BGG, GBB, GBG, BGB, BBB, and GGG
therefore the probability of getting one boy and two girls is

also the probability of getting 3 girls is
It's a perfect square because 8 times 8 equals 64.