in the hillside summer camp there are 50 children . 90 % of the children are boys and the rest are girls . the camp administrator decided to make the number of girls only 20 % of the total number of children in the camp . how many more boys must she bring to make that happen ?
"given there are 50 students , 90 % of 50 = 45 boys and remaining 5 girls . now here 90 % are boys and 10 % are girls . now question is asking about how many boys do we need to add , to make the girls percentage to or 20 % . . if we add 35 to existing 45 then the count will be 80 and the girls number will be 20 as it . now boys are 80 % and girls are 20 % . ( out of 100 students = 80 boys + 20 girls ) . imo option a is correct ."
add(multiply(divide(subtract(const_100, 20), const_100), 50), multiply(divide(20, const_100), 50))