Saturday: 2980 visitors.
540 fewer on Saturday than on Sunday means Sunday had MORE visitors.

• Sunday = Saturday + 540 = 2980 + 540 = 3520
• Total for two days = Saturday + Sunday
• = 2980 + 3520 = 6500

6500 people visited the park during the two days.
Check: 3520 − 2980 = 540 (difference is correct). ✓