The number of students in three classes are in the ratio

The number of students in three classes are in the ratio 2 : 3 : 4. If 12 students are increased in each class, this ratio changes to 8 : 11 :14. The total number of students in the three classes at the beginning was

Let the original number of students be 2x, 3x and 4x in three class.
According to the question,

2x + 12	=	8
3x + 12	=	11

⇒ 24x + 96 = 22x + 132
⇒ 2x = 132 – 96 = 36

⇒ x =	36	= 18
	2

∴ Original number of students
= 2x + 3x + 4x
= 9x = 9 × 18 = 162