the ratio 6/5 means for every 6 boys there are 5 girls.
Add the ratio: 6+5 = 11
Divide class total by 11: 22/11 = 2
Multiply each ratio number by 2 to find the number of boys and the number of girls:
6 x 2 = 12 boys
5 x 2 = 10 girls.
10 out of the 22 kids are girls.
The probability of picking a girl would be 10/22, which reduces to 5/11