Meaning of RATIO in English

RATIO

[noun] [C] [plural] ratios - the relationship between two groups or amounts, which expresses how much bigger one is than the otherThe ratio of men to women at the conference was ten to one/10:1.The school is trying to improve its pupil-teacher ratio (= the number of teachers compared with the number of students).

Cambridge English vocab.      Кембриджский английский словарь.