For a normal distribution, what percentage of data falls within one standard deviation of the mean?

What is the area of triangle abc if a = 8, b = 11, and c = 15?

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?

If abcde is reflected over the x-axis and then translated 3 units left, what are the new coordinates d?