A ratio can be worked out if the fraction of the whole is known.
The denominator gives the total amount. The numerator gives the amount of each part.
In a class of 32 students, 14 of them wear glasses. What is the ratio of wearers : non-wearers?
The fractions of wearers 14.
The fraction of non-wearers is 1 - 14 = 34.
Compare the numerators for the ratio 1:3.
Answer: 1:3
There are 24 cars in a car park. 14 are red, and 16 are silver. The remaining cars are blue. What is the ratio of red:silver:blue cars in the car park?
Find equivalent fractions with the same denominator.
Red cars: 14 = 624
Silver cars: 16 = 424
There are 14 cars remaining (24 - 6 - 4) = 1424
Compare the numerators 6:4:14, and simplify to 3:2:7.
(Note that there could be more than 24 cars, but the number of cars must be a multiple of 24 and the fractions and ratios would remain the same)
Answer: 3 : 2 : 7