A ratio is a way of showing how two or more quantities are related. For example, if there are double the number of boys in a class compared with the number of girls, then we can show this by writing 2:1. This would be read as: 'the ratio of boys to girls is two to one'. Two parts of the class are boys and one part is girls, but: what is 'part(s) of' as a fraction? It's easy: 2 + 1 = 3, so 2⁄3 are boys, and 1⁄3 is girls. You would deal with other ratios in a similar way.
Be warned: if you reverse the order of the numbers in a ratio, the ratio changes. 2:1 is NOT the same as 1:2. The order in which you write your ratio is important. Finally, ratios can be simplified by dividing/multiplying the ratio by another number, e.g. 4:8 can be written as 1:2 by dividing both numbers in the ratio by 4.
Play this 11-plus Maths quiz and see how well you do.
This quiz is for members only, but you can play our Addition and Subtraction (Very Easy) quiz to see how our quizzes work.
If you're already a subscriber, you can log in here
Or take a look at all of our 11-Plus Maths quizzes.
Or if you're ready to take the plunge, you can sign up here.