Mathematics. Use 22/7

Wrong or other answers will be reported

A

Step-by-step 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

( to 2 d.p.)

i = 2 / - 5

step-by-step explanation:

evaluation of ( 2 - 4 ) ( p + q ) when p = 2 and q = 5 i, by putting values of p and q,                                                                    

see explanation

step-by-step explanation:

since the sequence is geometric there is a common ratio r between consecutive terms, that is

r = 4 ÷ - 2 = - 2

r = - 8 ÷ 4 = - 2

r = 16 ÷ 8 = - 2

the next term - 13 must be incorrect as it should be - 32 for the sequence to be geometric.

the first 4 terms are therefore geometric with common ratio r = - 2