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

### Instruction:
What is the rank for Mar 17 when the April 21 rank is 10?

### Inputs:
table_name: table, columns: ['Poll', 'Pre- season', 'Mar 3', 'Mar 17', 'Mar 24', 'Mar 31', 'April 7', 'April 14', 'April 21', 'April 28', 'May 5', 'May 12', 'May 19', 'May 26', 'Final']

### Response:
SELECT Mar 17 FROM table WHERE April 21 = 10