Question

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 10 cm. To get the wax for the candle, Devin melts cubes of wax that are each 4 cm by 4 cm. How many of the wax cubes will Devin need in order to make the candle?

Answer 1

In order to determine the number of wax cubes needed to make the candle, we divide the volume of the pyramid by the volume of the cube. That is,
number of wax = volume of mold / volume of wax
The formulas are,
number of wax = (1/3)Ah / s³
Where A is the area of the base, in this case 9 cm x 9 cm which is equal to 81 cm². Substituting the known values from the given above,
number of wax = (1/3)(81 cm²)(10 cm) / (4 cm)³ = 4.21
Thus, approximate number of wax should be 4.21. If we are to round this off to the nearest whole number, we will get 5 (considering that we want rather to have excess than missing items)