2011 AMC 10A Problems/Problem 8

Revision as of 10:48, 11 February 2011 by Lord.of.AMC (talk | contribs) (Problem 8)

Problem 8

Last summer 30% of the birds living on Town Lake were geese, 25% were swans, 10% were herons, and 35% 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

75% of the total birds were not swans. Out of that 75%, there was $30\% \cdot 75\% = \boxed{40\%}$ of the birds that were not swans that were geese. (C)