Answer :
Well, y=ny
2(y-1)=ny
(where ny is not-yellow)
You get y=2y-2 or y=2. You had two yellow birds and two other types.
2(y-1)=ny
(where ny is not-yellow)
You get y=2y-2 or y=2. You had two yellow birds and two other types.
[tex]x - all\ birds\\ \\ \frac{1}{2} x \ -\ the\ yellow\ birds\\ \\ \frac{1}{2} x-1=\frac{1}{3} x\ \ /\cdot6\\ \\ 3x-6=2x\\ \\x=6\ \ \ \Rightarrow\ \ \ \frac{1}{2} x=\frac{1}{2} \cdot 6=3\\ \\ Ans.\ 3\ yellow\ birds[/tex]