Boats 2

Three-quarters of the boats in the marina are white. 4/7 out of the remaining boats are blue, and the rest are red if there are nine red boats. How many boats are in the marina?

Final Answer:

n =  84

Step-by-step explanation:

$$\begin{gathered} 3/4\cdot n+4/7\cdot (n-3/4\cdot n)+9=n \\ 3n=252 \\ n=\frac{252}{3}=84 \\ n=84 \end{gathered}$$

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