If you filled out the chart fully: 
a = 4 
b = 7 
c = 6 
d = 9 
e = 17 
Based on the chart, their 7 girls and 10 boys. In this case, it is a better chance of selecting a boy which ratio is: 
7:10 
There is a greater chance of picking a boy than a girl where there is three more boys than girls.