Normal Probability distributions: The reported scores on a nationally standardized achievement test for high school graduates have a mean of 500 with...

Normal Probability distributions:  The reported scores on a nationally standardized achievement test for high school graduates have a mean of 500 with the standard deviation of 100.  The scores of are approximately normally distributed, what is the probability that the score of a randomly chosen individual will be (a) between 500 and 650? And (b) between 450 and 600?