Answer:
total number of students is 2500
ratio is 18:7
Explanation:
we can use cross multiplication
since 72% of the school are boys and number of boys is 1800
means that :
72% * x = 1800
NB : is the number of students in the school
x = 1800/72%
x = 1800/0.72
x = 2500
total number of students is 2500
the number of girls in the school
2500 - 1800
= 700 girls
ratio of boys to girls
1800 : 700
can divide by 100
18 : 7