4. suppose a laboratory has a 31 g sample of polonium-210. the half-life of
polonium-210 is about 138 days.
a. how many half-lives of polonium-210 occur in 966 days?
b. how much polonium is in the sample 966 days later?

Find the number of liters in 12.8 gal of gasoline. round to the nearest hundredths

The two cylinders are similar. if the ratio of their surface areas is 9/1.44 find the volume of each cylinder. round your answer to the nearest hundredth. a. small cylinder: 152.00 m3 large cylinder: 950.02 m3 b. small cylinder: 972.14 m3 large cylinder: 12,924.24 m3 c. small cylinder: 851.22 m3 large cylinder: 13,300.25 m3 d. small cylinder: 682.95 m3 large cylinder: 13,539.68 m3

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.