Question : In $\triangle$PQR, $\angle$ PQR = $90^{\circ}$, PQ = 5 cm and QR = 12 cm. What is the radius (in cm) of the circumcircle of $\triangle$PQR?

Option 1: 6.5

Option 2: 7.5

Option 3: 13

Option 4: 15

Question : If AB = 5 cm, AC = 12 cm, and AB$\perp$ AC, then the radius of the circumcircle of $\triangle ABC$ is:

Option 1: 6.5 cm

Option 2: 6 cm

Option 3: 5 cm

Option 4: 7 cm

Question : In $\triangle$ ABC, $\angle$ BCA = $90^{\circ}$, AC = 24 cm and BC = 10 cm. What is the radius (in cm) of the circumcircle of $\triangle$ ABC?

Option 1: 12.5

Option 2: 13

Option 3: 25

Option 4: 26

Question : The ratio of the total surface area and volume of a sphere is 2 : 7. Its radius is:

Option 1: 7.5 cm

Option 2: 10.5 cm

Option 3: 10 cm

Option 4: 7 cm

Question : ABC is a right-angled triangle with AB = 6 cm and BC = 8 cm. A circle with centre O has been inscribed inside $\triangle ABC$. The radius of the circle is:

Option 1: 1 cm

Option 2: 2 cm

Option 3: 3 cm

Option 4: 4 cm