Answer:
(c) 115.2 ft³
Step-by-step explanation:
The volume of a composite figure can be found by decomposing it into figures whose volumes are easy to compute. Here, the figure can be nicely represented as a cube and a square pyramid.
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<h3>Cube</h3>
The volume of the cube on the left is given by ...
V = s³
V = (4.2 ft)³ = 74.088 ft³
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<h3>Pyramid</h3>
The volume of the pyramid on the right is given by ...
V = 1/3Bh . . . . . where B is the area of the square base
V = 1/3(s²)h = (4.2 ft)²(7 ft) = 41.16 ft³
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<h3>Total</h3>
The volume of the composite figure is the sum of these volumes:
cube volume + pyramid volume = 74.088 ft³ +41.16 ft³ = 115.248 ft³
The volume of the composite figure is about 115.2 ft³.
9514 1404 393
Answer:
2∛7
Step-by-step explanation:
Putting the expression in simplest form will factor cubes from under the radical.
![\displaystyle\sqrt[3]{56}=\sqrt[3]{2^3\cdot7}=\boxed{2\sqrt[3]{7}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Csqrt%5B3%5D%7B56%7D%3D%5Csqrt%5B3%5D%7B2%5E3%5Ccdot7%7D%3D%5Cboxed%7B2%5Csqrt%5B3%5D%7B7%7D%7D)
The answer is 3.25 or 3 1/4
Given:
First term of an arithmetic sequence is 2.
Sum of first 15 terms = 292.5
To find:
The common difference.
Solution:
We have,
First term: 
Sum of first 15 terms: 
The formula of sum of first n terms of an AP is
![S_n=\dfrac{n}{2}[2a+(n-1)d]](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7Bn%7D%7B2%7D%5B2a%2B%28n-1%29d%5D)
Where, a is first term and d is common difference.
Putting , n=15 and a=2 in the above formula, we get
![292.5=\dfrac{15}{2}[2(2)+(15-1)d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B2%282%29%2B%2815-1%29d%5D)
![292.5=\dfrac{15}{2}[4+14d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B4%2B14d%5D)
![292.5=15[2+7d]](https://tex.z-dn.net/?f=292.5%3D15%5B2%2B7d%5D)
Divide both sides by 15.
Dividing both sides by 7, we get
Therefore, the common difference is 2.5.
