In a library, the ratio of fiction books to non-fiction books is 1:41:41:4. The non-fiction books are all either history books or science books. The ratio of history books to science books is 7:37:37:3.
What percentage of all the books in the library are science books?
60 exam-style questions on AQA GCSE Maths Writing a Ratio as a Fraction or Linear Function. Each one has a worked solution and a mark scheme showing where the marks go.