A cup, when full, contains 3/10 litres of
water. A bucket, when full, contains
9 litres of water. How many of these
cups are needed to fill the bucket
completely?

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