Answer:
• The number of advance tickets sold: 25
• The number of same-day tickets sold: 35
Step-by-step explanation:
Let the number of advance tickets sold = a
Let the number of same-day tickets sold = s
Advance tickets = $25
Same-day tickets = $40.

From equation (1):

Substitute a=60-s into the second equation:

Recall: a=60-s

Therefore:
• The number of advance tickets sold: 25
,
• The number of same-day tickets sold: 35