Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the smallest average for Beijing Guo'an when they played more than 240 games?

### Inputs:
table_name: table, columns: ['Season', 'Total Attendance', 'Games', 'Average', 'High avg.', 'Team', 'No. Of Clubs']

### Response:
SELECT MIN Average FROM table WHERE Team = beijing guo'an AND Games > 240