Here are

Here are white, blue, and red boats in a marina. Two-thirds of the boats in the marina are white, 4/7 of the remaining boats are blue, and the rest are red. If there are 15 red boats, how many boats are in the marina?

Which tape diagram represents how many of the boats are white?

Correct answer:

n =  105

Step-by-step explanation:

$$\begin{gathered} 2/3\cdot n+4/7\cdot (n-2/3\cdot n)+15=n \\ 3n=315 \\ n=\frac{315}{3}=105 \\ n=105 \\ \text{ Verifying Solution: } \\ w=2/3\cdot n=2/3\cdot 105=70 \\ b=4/7\cdot (n-2/3\cdot n)=4/7\cdot (105-2/3\cdot 105)=20 \end{gathered}$$

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