a standard normal random variable

a standard normal random variable, compute the following probabilities:
1. P(-1.98<= z <=.49)
2. P(.52<=.z <= 1.22)
True or False
3. A + A' always equals zero.
4.If the variance equals zero, the values of z must add up to zero (ex. 1,-1,2,-2)
5.The normal distribution curve does not have to be symmetric to zero.