Part A: a rational number between 5.2 and 5.5 is 5.3 repeating (5.333333...)
It is a rational number since it can be written as a fraction. (5 1/3)
Part B: an irrational number between 5.2 and 5.5 is something like 5.94513879618868726.... (sorry i just spammed the number pad) That is because it goes on forever with no pattern, and can't be written as a fraction.