Answer :
35x + 20y = 7620
x+y=276
Y=276-x
35x+20(276-x)=7620
35x+5520-20x=7620
15x=2100
X=140
140+y=276
Y=136
140 adults and 136 children
x+y=276
Y=276-x
35x+20(276-x)=7620
35x+5520-20x=7620
15x=2100
X=140
140+y=276
Y=136
140 adults and 136 children