3 girls / 5 boys = 12 girls / x.
x=( 5 boys * 12 girls) / 3 girls= 20 boys.
You can also do it by a rule of 3:
3 girls---------------------5 boys
12 girls-------------------- x
x=( 5 boys * 12 girls) / 3 girls= 20 boys.
Total students=12 girls + 20 boys= 32 students.
Answer: There are 20 children and 32 students in total, in room 701.
