If the letters a-l-g-e-b-r-a are chosen randomly, what is the probability that the chosen letter is an a?

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?

Can someone me do math because i am having a breakdown rn because i don’t get it

If angle b measures 25°, what is the approximate perimeter of the triangle below? 10.3 units 11.8 units 22.1 units 25.2 units