A ratio is used to compare two quantities. The quantities should be in the same units.
Part ofMathsNumeracy
The ratio of girls to boys in the school disco was \(3 : 1.\)
If there were \(50\) boys there, how many girls were at the disco?
Boys = 1 part = \(50\) pupils
Girls = 3 parts = \(3 \times 50 = 150\) pupils
There were \(150\) girls at the disco.
The ratio of girls to boys at the school jumble sale was \(1 : 2\).
If there were \(20\) boys there, how many girls were at the jumble sale?
Boys = 2 parts = \(20\) pupils, so 1 part = \(10\) pupils.
Girls = 1 part = \(10\) pupils.
There were \(10\) girls at the jumble sale.
