Answer:
20
Step-by-step explanation:
If the ratio of boys is 9 there are 90 boys. If 9=90 then 1= 10. 10 x 2 = 20
I hope this helps :0)
20 girls
Step-by-step explanation:
For every 9 boys there are 2 girls, so, if we have 90 boys, 9x10=90 and then since we have the 10 we use it to do 2x10 to get 20 girls
