A school contains 1200 students, 3/5 are male. Years 9,10&11 are split in ratio for boys 3:4:2 and for the girls 4:5:3. How many of each gender are there in each year group?

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

Step-by-step 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