Three quarters of the boats in the marina are white, 4/7 of the remaining boats are blue, and the rest are red. if there are 9 red boats, how many boats are in the marina

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