Identify a1 in the following sequence: 72, 48, 32, 64/3

Find the area of a parallelogram with base 15 yards and height 21 2/3

This is about circle theorems. someone asap : (

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