I need help on this please

Anne is twice as old as bill, and bill is 3 years older than christie. the sum of anne s and christie s ages equal 72. find their age difference.?

The annual snowfall in a town has a mean of 38 inches and a standard deviation of 10 inches. last year there were 63 inches of snow. find the number of standard deviations from the mean that is, rounded to two decimal places. 0.44 standard deviations below the mean 2.50 standard deviations below the mean 0.44 standard deviations above the mean 2.50 standard deviations above the mean

Solve for n? [tex]z = \frac{3}{4} mn[/tex]