Help worth 20 points I need a expert to do this

1 CD    = $16.50

2 CD's = $28.50

3 CD's = $40.50

Step-by-step explanation:

1 is

for 1 disc is $16.50

for 2 disc is $33.00

for 3 disc is $49.50

and

2 is

for 1 book is $6.95

for 2 books is $13.90

for 3 books is $20.85

Step-by-step explanation:

brainliest pls

C. π(2ft)²(10ft) + 1/3π(2ft)²(13ft-10ft)

Step-by-step explanation:

Given:

diameter = 4ft

length of the cylindrical part = 10ft

entire length of the silo = 13ft

Find the volume of the silo = volume of cylinder and volume of the cone

Formulas:

Volume of cylinder: πr²h

Volume of come: 1/3πr²h

2ft= radius

height =10

volume π×2²×10

radius 2ft

height 13-10=3ft

Volume= 1/3×π×2²×3 cube feet

Therefore the third answer is correct: C. π(2ft)²(10ft) + 1/3π(2ft)²(13ft-10ft)