Answer:
A) 84 cubes
B) Volume = 4 x 3 x 7 = 84 small cubes
[tex]\sf Volume=3 \frac{1}{9}\:\:ft^3[/tex]
Step-by-step explanation:
Part A
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:
[tex]\sf Length=1 \frac{1}{3}\:ft=\dfrac{4}{3}\:ft=4\:thirds[/tex]
[tex]\sf Width=1 \:ft=\dfrac{3}{3}\:ft=3\:thirds[/tex]
[tex]\sf height=2 \frac{1}{3}\:ft=\dfrac{7}{3}\:ft=7\:thirds[/tex]
Now simply multiply the number of thirds:
Number of cubes in prism = 4 x 3 x 7 = 84
Part B
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:
[tex]\textsf{Volume of small cube}=\sf \dfrac{1}{3} \times \dfrac{1}{3} \times \dfrac{1}{3}=\dfrac{1}{27}\:ft^3[/tex]
Now multiply the volume in terms of number of cubes by the actual volume of a cube:
[tex]\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}[/tex]
