Difference between revisions of "2011 AMC 12A Problems/Problem 5"

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Revision as of 20:51, 3 July 2013

Problem

Last summer $30%$ (Error compiling LaTeX. Unknown error_msg) of the birds living on Town Lake were geese, $25%$ (Error compiling LaTeX. Unknown error_msg) were swans, $10%$ (Error compiling LaTeX. Unknown error_msg) were herons, and $35%$ (Error compiling LaTeX. Unknown error_msg) were ducks. What percent of the birds that were not swans were geese?

$\textbf{(A)}\ 20 \qquad \textbf{(B)}\ 30 \qquad \textbf{(C)}\ 40 \qquad \textbf{(D)}\ 50 \qquad \textbf{(E)}\ 60$

Solution

To simplify the problem, let us say that there were a total of $100$ birds. The number of birds that are not swans is $75$. The number of geese is $30$. Therefore the percentage is just $\frac{30}{75} \times 100 = 40 \Rightarrow \boxed{C}$

See also

2011 AMC 12A (ProblemsAnswer KeyResources)
Preceded by
Problem 4
Followed by
Problem 6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions

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