Question

0. The average marks of the students in four sections A, B, C and
D together is 60%. The average marks of the students of
A, B, C and D individually are 45%, 50%, 72% and 80%
respectively. If the average marks of the students of sections A
and B together is 48% and that of the students of B and C
together is 60%. What is the ratio of number of students in
sections A and D?​

Answer 1

=> If A,B,C,D are number of students in section A,B,C,D respectively , then

45A+50B+72C+80D= 60*(A+B+C+D)

-15A-10B+12C+20D=0

also 48A+48B= 45A+50B or B=2/3 A

and 60B+60C= 50B+72C; B=6/5 C; C=5/9 A

solving these equations,

A/D =4/3 ans

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