Michelle has a $100. she wants to purchase paper pins ($20) and file covers ($20) and paper weights. each paper weight costs $10. how many paper weights can she purchase?

Orla and eduardo each looked at a strand of their hair under a microscope and measured the diameter. orla's strand was 0.005\,\text{cm}0.005cm in diameter, and eduardo's strand was 0.012\,\text{cm}0.012cm in diameter.