International PI Day Challenge (Junior)

The volume of a sphere is given by the formula V=⁴/₃ πr³, where r is the radius. Express r in terms of V and π

• ( √^3v/_4π)³

• ( ³√^3v/_4π)

• √^4π/_3v

• ( ³√^4π/_3v)³

If the circumference of a circle is 72cm, its radius is .... (Take π = ²²/₇)

• 9.3 cm

• 10.35 cm

• 11.25 cm

• 11.45 cm

The area of a circle whose diameter is 7 cm is _____. (Take π = ²²/₇)

• 22 cm²

• 38 cm²

• 38.5 cm²

• 44 cm²

Make d the subject of the formular 3πd = V

• ^v/_3d

• ^3d/_v

• ^v/_3π

• ^v/_3πd

Given that V=πr²h, express r in terms of V, π and h

• r = √^h/_πV

• r = √^Vπ/_h

• r = √^πh/_r

• r = √^V/_πh

Pi equals ____________

• 3.14159

• 3.14897

• 3.14239

• 3.14888

Calculate the circumference of a circle whose radius is 3.5 cm ( π = ²²/₇)

• 11 cm

• 22 cm

• 44 cm

• 55 cm

Calculate the area of a circle whose radius is 7cm. (Take π = ²²/₇)

• 130 cm²

• 154 cm²

• 209 cm²

• 949 cm²

Calculate the perimeter of a circle of radius 7cm (π= ²²/₇)

• 11 cm

• 22 cm

• 33 cm

• 44 cm

The diameter of a circle is 14 cm, what is the difference between the perimeter and area of the circle

• 100

• 110

• 140

• 150