A new exam to cover a topic "System of General Inequalities" has been released to UNIZOR.COM - Math 4 Teens - Algebra. It contains six multiple choice problems. Highly recommended for those who seek Knowledge.

1. What is a solution to the following inequality?
(x² + y² −16)·(x² + y² − 36) < 0

2. What is the area S of the part of a coordinate plane defined by the following inequality?
(x² + y² − 25)·(x² + y² − 49) > 0

3. What is the area S of the part of a coordinate plane defined by the following system of inequalities?
x² + y² − 4 < 0
y − x < 0

4. What is the perimeter P of the part of a coordinate plane defined by the following system of inequalities?
x² − 4 < 0
y² − 16 < 0

5. What is the perimeter P of the part of a coordinate plane defined by the following system of inequalities?
x² + y² − 9 < 0
x + y < 0

6. The part of a coordinate plane is defined by the following inequalities?
x² + y² − R² < 0
y − |x| < 0
What is the value of parameter R, if the area of thus defined part of a coordinated plane equals to 48π?