Which of the following equations have infinitely many solutions?

Suppose there are 10 five and six-year-old attending a birthday party. when a 30 year old mother walks into the room with an infant in her arms, what happens to the mean age in the room? what happens to the standard deviation of ages in the room? a. the mean and standard deviation of both change. b. the meaning will change, but the standard deviation will stay approximately the same. c. i mean will stay approximately the same, but the standard deviation will change. d. the mean and standard deviation will both stay approximately the same.

The interior angles formed by the side of a hexagon have measures of them up to 720° what is the measure of angle a

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)