Answer:
For boys
Year 9 = 240 boys
Year 10 = 320 boys
Year 11 = 160 boys
For girls
Year 9 = 160 girls
Year 10 = 200 girls
Year 11 = 120 girls
Explanation:
A school contains 1200 students, 3/5 are male.
The first step would be to calculate how many boys are in the school
= 1200 × 3/5
= 720 boys.
This means the number of girls in school is calculated as:
= 1200 - 720
= 480 girla
A) Years 9,10&11 are split in ratio for boys 3:4:2
Total number of boys = 720
Adding up the ratios
3 + 4 + 2 = 9
Year 9
= 3/9 × 720
= 240 boys
Year 10
4/9 × 720
= 320 boys
Year 11
2/9 × 720
= 160 boys
The girls for the girls 4:5:3.
Total number of students that are girls = 480 students
Adding the ration together
= 4 + 5 + 3 = 12
Year 9
= 4/12 × 480
= 160 girls
Year 10
= 5/12 × 480
= 200 girls
Year 11
= 3/12 × 480
= 120 girls
Therefore,
For boys
Year 9 = 240 boys
Year 10 = 320 boys
Year 11 = 160 boys
For girls
Year 9 = 160 girls
Year 10 = 200 girls
Year 11 = 120 girls