I will now explain the fastest way to solve this. First off, the ratio is 2:3 so the first thing I do is combine that for 5, then do 30/5 for an answer of 6. Then, I multiply 6 for the ratio, which comes out as 12:18, 12 boys and 18 girls. 18-12=6, so there are 6 more girls than boys in the class.