 
 <prompt> ```On top 16 GB (gigabyte) USB drive, 50% don already full. Calculate how many gigabytes still remain.``` <response>: ```We calculate 50% of 16 GB:
50/100 * 16 GB = 0.5 * 16 GB = 8 GB
That leaves 16 GB - 8 GB = 8 GB available on this key.

The final answer: 8.``` 