Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
Tilly needs to sell 100 bags at $10 per bag to make $300 in profit. How much did she buy each bag for?

### Response:
Tilly will make 100 x $10 = $<<100*10=1000>>1000 in total
She has spent $1000 - $300 = $<<1000-300=700>>700 on 100 bags.
Each bag cost Tilly $700 / 100 bags = $<<700/100=7>>7.
#### 7