In a school there are 10 boys and 11 girls. 25 more girls joined the school. How many more girls than boys does the school have?
There are 10 boys and 11 girls in the school. 

25 more girls joined the school. 

That means there are now a total of 36 girls in the school. 

There are still 10 boys in the school. 

That means there are 26 more girls than boys in the school.