Question

Pls help me with these 4 questions.

1.The volume of a right rectangular prism is 7 1/2 cm³. The height of the prism is 2 1/4 cm.

What is the area of the base of the prism?

3 1/3 cm²

5 1/4 cm²

9 3/4 cm²
2.What is the exact volume of this cone? (look at the first pic)

32/3π in³

80/3π in³

320/3π in³
3.This prism is being used as a planter for small plants to keep on a windowsill.

How much dirt will it take to completely fill 4 of these planters?(2nd pic)
115 1/2 cm³

361 cm³

462 cm³
4.Cone X has a diameter of 20 ft and a height of 16 ft. Cone Y is the same height as cone X, but its diameter is twice the diameter of cone X.

What is the difference in the volumes of the two cones?

Use π≈3.14 .


5,024 ft³

15,072 ft³

20,096 ft³

Answer 1

5024 ft³

Explanation:

Answer 2

see below

Explanation:

1. 7 1/2 ÷ 2 1/4 = 3 1/3 cm²

2. Volume of a cone =
`(1)/(3)\pi r^2h = (1)/(3)\pi * 4^2 *5=(80)/(3) \pi` in³

3. Volume of planter = 3 1/2 x 6 x 5 1/2 = 115.5

4 planters = 115.5 x 4 = 462 cm³

4. Cone X volume =
`(1)/(3)\pi r^2h = (1)/(3) *3.14 * 10^2 *16=(5024)/(3)`

Cone Y volume =
`(1)/(3)\pi r^2h = (1)/(3) *3.14 * 20^2 *16=(20096)/(3)`

Difference = 5024 ft³