Algebra · Percentages · Fractions of a whole · Complementary counting · Ratios
Birds have gathered on a large pond. Exactly one third of them are swans and all the remaining birds are ducks. It turns out that \(70\%\) of all the birds on the pond are white, and every one of the swans is among these white birds. What percentage of the ducks on the pond are white?
- A \(45\)
- B \(55\)
- C \(60\)
- D \(65\)
- E \(66\frac{2}{3}\)
Sign in to check answers, open hints, read the full solution, and track your progress. Statements are always free.
Slovenian High School Mathematics Competition for Vega Awards (MaSSA), drzavno (national) round 2025, 1. letnik, category A, problem A3. Organized by DMFA Slovenije (Society of Mathematicians, Physicists and Astronomers of Slovenia). Source