Mathematics for IGCSE & O level - Ratio And Proportion (Section 6 - No. 10)
If the ratio of boys to girls in a class is 2:3 and there are 10 boys. How many students in total are in the class?
15
20
25
30
คำอธิบาย
2 parts = 10, hence each part = 5. 3 parts for girls = 15. Therefore, total students = 15+10=25.