You have at least two options:
Option 1: Calculate Pr(X < 1) and Pr(X > 2) using the given mean and standard deviation and obtain 0.25 and 0.05.
Option 2: Calculate the mean and standard deviation directly from the given information. To do this, first calculate (using tables, technology or however you've been taught how to do it) the Z-values a and b such that Pr(Z < a) = 0.25 and Pr(Z > 2) = 0.05. Then:
Substitute the values of a and b and solve equations (1) and (2) simultaneously for the mean and the standard deviation.