I have two questions that seem to be the same. One is if the mean is 3.5 and the standard deviation is .5 and Sally's score is 1.5. How many standard deviations is Sally from the mean? The other is if Billy's score is 5, what is his standard score? Don't both of these questions utilize the same formula? Z = x-means divided by the standard deviation?

Yes, both use the same formula: Sally's "z-score" is (1.5-3.5)/0.5 = -4 sigma from the mean. Billy's z-score is (5-3.5)/0.5 = +3 sigma.