Alandscape company charges $100 plus $15 per hour. another company charges $75 plus $17 per hour. how long is a job that costs the same no matter which company is used

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g