There are 11 boys and 13 girls in a class. If 1 boy is added to the class, what percentage of the class are girls?
There are a total of 11 + 1 = <<11+1=12>>12 boys in the class.
Hence, there are a total of 12 boys + 13 girls = <<12+13=25>>25 students in a class.
So 13/25 x 100% = 52% of the class are girls.
#### 52