Element X is a radioactive isotope such that every 13 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 60 grams, how much of the element would remain after 30 years, to the nearest whole number?

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?

Write the percent as a fraction or mixed number in simplest form. 0.8%