Pls help emergency will Mark bigbrain

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?

Acar travels at an average speed of 56 miles per hour. how long does it take to travel 196 miles

Plz ( true - false) all triangles have interior angles whose measure sum to 90.