Element X is a radioactive isotope such that every sixty nine years, its mass decreases by half. Given that the initial mass of a sample of Element X is 20 grams, how much of the element would remain after 30 years, to the nearest whole number?

Ray ce is the angle bisector of zacd, which statement about the figure must be true? mzecd-mzecb mzace « 4mzacd zace - zdcb zecd zacd save and exit

East black horse $0.25 total budget is $555 it'll cost $115 for other supplies about how many flyers do you think we can buy

Circle d circumscribes abc and abe. which statements about the triangles are true? statement i: the perpendicular bisectors of abc intersect at the same point as those of abe. statement ii: the distance from c to d is the same as the distance from d to e. statement iii: bisects cde. statement iv: the angle bisectors of abc intersect at the same point as those of abe. a. i only b. i and ii c. ii and iv d. i and iii e. iii and iv