Two spheres are similar. The ratio of their radii is 2:1. What is the ratio of their volumes? Please type your answer in the form of a ratio (x:y) with no spaces.

How many heads would you expect if you flipped a coin twice? first, fill in the table below with the correct probabilities. hint: the sample space for flipping a coin twice is {hh, ht, th, tt}. a = b = c = f