Answer:
A) 84 cubes
B) Volume = 4 x 3 x 7 = 84 small cubes
![\sf Volume=3 \frac{1}{9}\:\:ft^3](https://tex.z-dn.net/?f=%5Csf%20Volume%3D3%20%5Cfrac%7B1%7D%7B9%7D%5C%3A%5C%3Aft%5E3)
Step-by-step explanation:
<h3><u>Part A</u></h3>
As the lengths of each side of the small cube are ¹/₃ ft each, to find the number cubes in the rectangular prism, first find how many thirds are in each dimension of the prism:
![\sf Length=1 \frac{1}{3}\:ft=\dfrac{4}{3}\:ft=4\:thirds](https://tex.z-dn.net/?f=%5Csf%20Length%3D1%20%5Cfrac%7B1%7D%7B3%7D%5C%3Aft%3D%5Cdfrac%7B4%7D%7B3%7D%5C%3Aft%3D4%5C%3Athirds)
![\sf Width=1 \:ft=\dfrac{3}{3}\:ft=3\:thirds](https://tex.z-dn.net/?f=%5Csf%20Width%3D1%20%5C%3Aft%3D%5Cdfrac%7B3%7D%7B3%7D%5C%3Aft%3D3%5C%3Athirds)
![\sf height=2 \frac{1}{3}\:ft=\dfrac{7}{3}\:ft=7\:thirds](https://tex.z-dn.net/?f=%5Csf%20height%3D2%20%5Cfrac%7B1%7D%7B3%7D%5C%3Aft%3D%5Cdfrac%7B7%7D%7B3%7D%5C%3Aft%3D7%5C%3Athirds)
Now simply multiply the number of thirds:
Number of cubes in prism = 4 x 3 x 7 = 84
<h3><u>Part B</u></h3>
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As we have already found the dimensions of the prism in terms of the number of cubes, the volume of the prism in terms of the small cube is:
⇒ Volume = 4 x 3 x 7 = 84 small cubes
To find the volume of the prism in ft³, calculate the actual volume of the small cube:
![\textsf{Volume of small cube}=\sf \dfrac{1}{3} \times \dfrac{1}{3} \times \dfrac{1}{3}=\dfrac{1}{27}\:ft^3](https://tex.z-dn.net/?f=%5Ctextsf%7BVolume%20of%20small%20cube%7D%3D%5Csf%20%5Cdfrac%7B1%7D%7B3%7D%20%5Ctimes%20%5Cdfrac%7B1%7D%7B3%7D%20%5Ctimes%20%5Cdfrac%7B1%7D%7B3%7D%3D%5Cdfrac%7B1%7D%7B27%7D%5C%3Aft%5E3)
Now multiply the volume in terms of number of cubes by the actual volume of a cube:
![\begin{aligned}\textsf{Volume} &= \sf \textsf{Volume in cubes} \times \textsf{Volume of cube in ft}^3\\\\& = \sf 84 \times \dfrac{1}{27}\:ft^3\\\\& =\sf \dfrac{84}{27}\:ft^3\\\\& =\sf 3\frac{1}{9}\:ft^3\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%5Ctextsf%7BVolume%7D%20%26%3D%20%5Csf%20%5Ctextsf%7BVolume%20in%20cubes%7D%20%5Ctimes%20%5Ctextsf%7BVolume%20of%20cube%20in%20ft%7D%5E3%5C%5C%5C%5C%26%20%3D%20%5Csf%2084%20%5Ctimes%20%5Cdfrac%7B1%7D%7B27%7D%5C%3Aft%5E3%5C%5C%5C%5C%26%20%3D%5Csf%20%5Cdfrac%7B84%7D%7B27%7D%5C%3Aft%5E3%5C%5C%5C%5C%26%20%3D%5Csf%203%5Cfrac%7B1%7D%7B9%7D%5C%3Aft%5E3%5Cend%7Baligned%7D)