Two classes of an school A ( Avg score -70) and B ( Avg score -45 ) are combined in a certain ratios to form two new classes C and D .If classes C and D are combined in the ratio of 1:2 to form new class E. Avg Score of new class is 60. If avg score of class C is 50 , in what ratio were class A and B are combined to form class D??

Question

Answer 1

Hey Kavya,Since average of class E is 60 and C&D are combined in ratio of 1:2 andwe know the avg of C which is 50 so we can easily find average of D =(50+2D)/3=60 making average of D as 65. Now to make 65 we can combine A and B in ratio 20:5 =((20*70)+(5*45))/25 =65.

Answer 2

Hey Kavya,Since average of class E is 60 and C&D are combined in ratio of 1:2 andwe know the avg of C which is 50 so we can easily find average of D =(50+2D)/3=60 making average of D as 65. Now to make 65 we can combine A and B in ratio 20:5 =((20*70)+(5*45))/25 =65.

Answer 3

But how u directly conclude that for A:B it will be 20:5

Answer 4

But how u directly conclude that for A:B it will be 20:5

Answer 5

Thanks

Answer 6

Thanks

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