Pyramid A is a square pyramid with a base side length of 18 inches and a height of 9 inches. Pyramid B has a volume of 3,136 cubic inches. How many times bigger is the volume of pyramid B than pyramid A? Give your answer as a percentage. Provide an explanation and proof for your answer to receive full credit.

1 answer

To solve the problem, we first need to calculate the volume of Pyramid A and then compare it to the volume of Pyramid B to find how many times bigger Pyramid B's volume is than Pyramid A's volume.

Step 1: Calculate the volume of Pyramid A.

The formula for the volume \( V \) of a pyramid is: \[ V = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]

Base Area of Pyramid A:

Since Pyramid A has a square base, we can calculate the base area as: \[ \text{Base Area} = \text{side length}^2 = 18^2 = 324 \text{ square inches} \]

Height of Pyramid A:

The height of Pyramid A is given as 9 inches.

Volume of Pyramid A:

Now we can substitute these values into the volume formula: \[ V_A = \frac{1}{3} \times 324 \times 9 \] Calculating this: \[ V_A = \frac{1}{3} \times 2916 = 972 \text{ cubic inches} \]

Step 2: Compare volumes of Pyramid A and Pyramid B.

The volume of Pyramid B is given as 3,136 cubic inches.

Step 3: Determine how many times bigger the volume of Pyramid B is than that of Pyramid A.

To compare the volumes, we can calculate the ratio: \[ \text{Ratio} = \frac{V_B}{V_A} = \frac{3136}{972} \]

Calculating this ratio: \[ \text{Ratio} \approx 3.225 (rounded to three decimal places) \]

Step 4: Convert the ratio to a percentage.

To find out how many times bigger Pyramid B is than Pyramid A in percentage, we take the ratio calculated, subtract 1 (the original volume of Pyramid A), and multiply by 100: \[ \text{Percentage Increase} = \left( \text{Ratio} - 1 \right) \times 100 \] Calculating this: \[ \text{Percentage Increase} = (3.225 - 1) \times 100 \approx 222.5 % \]

Conclusion

Pyramid B is approximately 222.5% bigger than Pyramid A's volume.

This indicates that Pyramid B's volume is more than three times the volume of Pyramid A, making it significantly larger in comparison.