Could you please explain these answers so if I got a similar question I could answer. Thanks.

1.

If a test has a mean of 500 and standard deviation of 100 (assuming a normal distribution). With N = 1000, about how many individuals score between 400 and 600?

2.

In a normal distribution of test scores, approximately _____ percent of the scores will fall within one standard deviation of the mean in either direction.