2x + x = 60 that is your equation. Simplify it and you get 3x = 60. 60/3 equals 20 so you have 20 boys but multiply it by 2 since you have twice as many girls and you get 40 girls total.
Girl = 2 parts Boy = 1 part So total = 2 + 1 = 3 parts and 60 children = 3 parts so 1 part will be 60 ÷ 3 = 20 students Multiply 20 to 2 and you will get 40 students.
