Element X decays radioactively with a half life of 9 minutes. If there are 960 grams of
Element X, how long, to the nearest tenth of a minute, would it take the element to
decay to 40 grams?

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?