Answer:
first 60 digits of pi: 3.14159265358979323846264338327950288419716939937510582097494
I think it is F, but I am a not sure.
Y = number of yellow fish
G = number of green fish
Y = G - 6
Y = 0.40 * (Y+G)
G - 6 = 0.4*(G-6+G)
G - 6 = 0.4*(2G-6)
G - 6 = 0.8G -2.4
0.2G = 3.6
G = 3.6/0.2=18
There are 18 green fish.
I believe the correct answer is D.
