Answer:
398 children
263 adults
Explanation:
Let the number of children be x and adults y. From the total attendance, we can write equation as x+y=661 hence y=661-x
Also, considering the charges then 1.5x+2y=1123
Replacing y with 661-x then
1.5x+2(661-x)=1123
1.5x-2x+1322=1123
0.5x=199
X=398
Y=661-x=661-398=263
Therefore, children were 398 and adults 263