V=3s2hThe formula gives the volume of a right square pyramid of height h and square base of side length s. If the side length of a right square pyramid increases by 30% while the height remains constant, what happens to the volume?Choose 1 answer:(A) The volume increases by 30%.(B) The volume increases by 69%.(C) The volume increases by 169%.(D) The volume increases by 300%.
Q. V=3s2hThe formula gives the volume of a right square pyramid of height h and square base of side length s. If the side length of a right square pyramid increases by 30% while the height remains constant, what happens to the volume?Choose 1 answer:(A) The volume increases by 30%.(B) The volume increases by 69%.(C) The volume increases by 169%.(D) The volume increases by 300%.
Denoting original side length: Let's denote the original side length of the square base as s and the height of the pyramid as h. The original volume V of the pyramid is given by the formula V=3s2⋅h. Now, if the side length increases by 30%, the new side length s′ will be s′=s+0.30s=1.30s. We need to calculate the new volume V′ with the increased side length and compare it to the original volume V to find the percentage increase.
Calculating new side length: Using the formula for the volume of the pyramid with the new side length s′, the new volume V′ is V′=3(1.30s)2×h. We need to square the new side length (1.30s)2 to find the factor by which the volume increases.
Calculating new volume: Calculating the square of the new side length gives us (1.30s)2=(1.30)2×s2=1.69×s2. This shows that the area of the base, and thus the volume, increases by a factor of 1.69 when the side length increases by 30%.
Expressing new volume in terms of original volume: Now we can express the new volume V′ in terms of the original volume V. Since V=3s2⋅h, the new volume V′ will be V′=31.69⋅s2⋅h=1.69V. This means the new volume is 1.69 times the original volume.
Calculating percentage increase in volume: To find the percentage increase in volume, we subtract the original volume from the new volume and then divide by the original volume: Percentage increase = ((V′−V)/V)×100%. Substituting V′=1.69V and V, we get Percentage increase = ((1.69V−V)/V)×100%=(0.69V/V)×100%=69%.
Conclusion: Therefore, the volume of the pyramid increases by 69% when the side length increases by 30% while the height remains constant. This corresponds to answer choice (B).
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