In a set of 100 ACT scores that are normally distributed and with a mean of 23

Question:

In a set of 100 ACT scores that are normally distributed and with a mean of 23 and standard deviation of 4.69,
(a) How many scores are expected to be lower than 18.31 (one standard deviation below the mean)?
(b) How many of the 100 scores are expected to be below 32.38 (two standard deviations above the mean)?