Mathematics for IGCSE & O level - Ratio And Proportion (Section 6 - No. 19)
In a class, the ratio of boys to girls is 5:4. If there are 36 students in the class, how many boys are there?
16
20
24
25
Explicació
Total ratio parts is 5+4 = 9. Boys represent 5/9 of the class: (5/9) * 36 = 20 boys.