<—-   Girls  ——–><- Boys—>                         

Group A       [ ——–u———][8][  u – 4  ]{4}        where {4}  is minus away

Group B       [————2u + 8 —————-](4)   where (4) is added on

(u+8)  + (2u+8)+ 4 – (u-4) = 56

2u + 24 = 56

2u = 32 => u = 16

Total students who went to the zoo(Group A + Group B) = 2(2u + 8) = 2[2(16) + 8] = 80

PS: Please click “Accept Answer” if the answer is correct else please state the answer key so that I can check the error.

Hi, the answer key stated that it’s 32.

The answer key is obviously wrong.   If there are already 56 girls, how can the total number of students (boys and girls) be 32 which is less than the total number of girls???