Terbium-160 has a half -life of about 72 days. After 396 days, about how many milligrams of a 220 mg sample will remain. A’ 5 mg B) 12 mg C) 40 mg D) 194 mg

Hurrya vegetable garden and a surrounding path are shaped like a square that together are 11ft wide. the path is 2ft wide if one bag of gravel covers 9 square feet how many bags are needed to cover the path