In an examination the average of all students in class A is 68 4 and that for students in class - Math - Statistics

Question

In an examination the average of all students in class A is 68 4
and that for students in class B is 71 2 If the average of both the
classes combined is 70, find the ratio of the no of students in
class A to the no of students in classB
Please do answer today only coz it's my exam tomm plzz
Thanks is u do :)

Manbar Singh · Accepted Answer

Let the number of students in class A = n1Let the number of students in class B = n2We have,average marks of class A = 68
4⇒sum of the marks of all the students in class Anumber of students in class A = 68
4⇒sum of the marks of all the students in class An1 = 68
4⇒sum of the marks of all the students in class A = 68
4 n1    
1average marks of class B =71
2⇒sum of the marks of all the students in class Bnumber of students in class B = 71
2⇒sum of the marks of all the students in class Bnumber of students in class B = 71
2⇒sum of the marks of all the students in class Bn2 = 71
2⇒sum of the marks of all the students in class B = 71
2 n2   
2Let average marks of both classes = 70⇒sum of the marks of all the students in class A + sum of the marks of all the students in class Bn1 + n2 = 70⇒68
4 n1 + 71
2 n2n1 + n2 = 70⇒70n1 + 70n2 =68
4 n1 + 71 2 n2⇒1 6 n1 = 1
2 n2⇒n1n2 = 1 21 6 = 34