There are 20 boys and 11 girls in the second grade and twice that number in the third grade. How many students are in grades 2 and 3?
There are 20 + 11 = <<20+11=31>>31 students in second grade.
There are 31 x 2 = <<31*2=62>>62 students in third grade.
In total, there are 31 + 62 = <<31+62=93>>93 students.
#### 93