Question

The ratio of the weight of a book to the weight of a mug is 7:5. What fraction of the total weight of the book and mug is the weight of the book?

Answer 1

7/12

Explanation:

You can pretend the given ratio units are the actual weights. Then the desired ratio is ...

book : mug = 7 : 5

book : (book +mug) = 7 : (7 +5) = 7 : 12

The weight of the book is 7/12 of the total weight.