Question

The students in three classes are in the ratio 2 : 3 : 5 .If 20 students are increased in each class,the ratio changes to 4:5:7.the total number of students before the increase were

Answer 1

Let x be the students in each class and y be the sum of all three class

2x+3x+5x= y

10x = y

if 20 students are added to each class ie 60 students are added

then ratio becomes 4:5:7

4x+5x+7x= y+60

16x= y+60

16x = 10x + 60

6x = 60

x= 10

hence total number of student before the student increase y=10x

y= 100

mark my ans brainlest if you agree