What is the distance from the sun to the asteroid belt in miles

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Fractions can be added and subtracted only if they're fractions. a. like b. proper c. improper d. unlike

Marina baked cookies. she gave 3/4 of the cookies to the scout bake sale. she shared the remaining 6 cookies with her friends. how many cookies did marina bake?