Question 13124
I am going to assume that you know the area of a circle is {{{PI (r^2)}}}
So, if you know the r (radius) you can calculate the area. Sometimes it is better not to multiply out by {{{PI}}} (3.14159) but just leave it as {{{PI}}}.
Your first question has a diameter of 4 on the outside, and a diameter of 2 on the inside. If you could find the areas of both of these circles, could you find the area of the ring? Try subtracting the area of the inner circle from the area of the outer circle!
Also, remember the diameter is twice the radius. So, putting this all to work:
The area of the outer circle is {{{PI(r^2)=PI(2^2)= PI(4)}}}
The area of the inner circle is {{{PI(r^2)=PI(1^2)=PI}}}
The area of their difference is {{{PI(4)-PI=PI(3)}}}

Your second question is similar except here you are dealing with the circumference of a circle, which is {{{2(PI)r}}}
You know what r is (6), so how far will the tip move in one hour? This is the circumference of the circle with a radius of 6. [Do the math]
But we want to know how far it moves in 36 minutes. Well, the hour is 60 minutes, so the part of the hour that the tip moves is 36/60 of the whole circumference. [Do the math] Do you get {{{PI(36/5)}}}?