Can someone work this out for me ? i'm so confused.

What is the least common multiple for 6 and 8? what is the least common multiple for 4 and 12 ? what is the least common multiple for 11 and 12? what is the least common multiple for 3 and 6?

The legs of a right triangle measure 6 meters and 8 meters. what is the length of the hypotonuse.

Atoss of a 20-sided die is equally likely to be any integer between 1 and 20 inclusive. what is the variance? provide your answer to two decimal points.