Devin is making a candle by pouring melted wax into a mold in the shape of a square pyramid. Each side of the base of the pyramid is 9cm and the height of the pyramid is 10cm. To get the wax for the candle, devin melts cubes of wax that are each 4cm by 4cm by 4cm. How many of the wax cubes will Devin need to make the candle? Please show work ❤

Respuesta :

Answer:

  5 cubes

Step-by-step explanation:

The volume of a square pyramid is given in terms of its side length (s) and height (h) as ...

  V = (1/3)s^2·h

For the given measurements, the volume is ...

  V = (1/3)(9 cm)^2 ·(10 cm) = 270 cm^3

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The volume of each cube of wax is the product of its length, width, and height, so is ...

  V = (4 cm)^3 = 64 cm^3

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Then the number of wax cubes required to fill the pyramid is ...

  (270 cm^3)/(64 cm^3/cube) = 4 7/32 cubes

Four cubes are not quite enough to make the candle.

Devin will need 5 cubes to make the candle.