Answer:
A= adult tickets, C=children tickets, S=senior tickets
A-10=C; C+10=A
4C=S
4C+6S+10A=1240, but S=4C and C=A-10
4C+24C+10C+100=1240
38C=1140
C=30 children tickets and $120
A=C+10=40 adult tickets and $400
4C=S=120 senior tickets and $720
$120+$400+$720= $1240.
