Question

Mathematics.... Use 22/7

Wrong or other answers will be reported

Answer 1

A

Explanation:

Volume of cylinder= πr²h, where r is the radius

Volume of concrete

= volume of large cylinder -volume of smaller hollow cylinder

Large cylinder:

Diameter= 7m

Since radius= ½(diameter),

Radius= 7 ÷2= 3.5m

Height= 3m

Volume of large cylinder

= π(3.5)²(3)

= 36.75π m³

Small hollow cylinder:

Diameter= 4m

Radius= 4 ÷2= 2m

Height= 3m

Volume of small hollow cylinder

= π(2)²(3)

= 12π m³

Substitute vol. of large and small hollow cylinder with 36.75π and 12π respectively, then substitute 22/7 for π:

Volume of concrete

= 36.75π -12π

= 24.75π

`= 24.75( (22)/(7) ) \\ = 77.79 \: m^(3)`

( to 2 d.p.)