Question

A pyramid has a square base with sides 100 feet long. The original height was 75 feet.

Answer 1

Step-by-step explanation:

Step 1:  Find the volume of the original pyramid

$V = a^2*\frac{h}{3}$

$V=(100)^2*\frac{75}{3}$

$V=10000*25$

$V=250000$

Step 2:  Find the volume of the cut off

$V=(20)^2*\frac{15}{3}$

$V = 400*5$

$V=2000$

Step 3:  Find the percent that still remains

$250000-2000$

$248000$

$248000 / 250000$

$0.992*100$

$99.2$

Answer:  99.2%

Answer 2

Answer:

99.2%

Step-by-step explanation:

Ratio of volumes = (Ratio of sides)³

Ratio of volumes = (15/75)³

Ratio of volumes = 1/125

1/125 × 100 = 0.8% was cut off

100 - 0.8 = 99.2% remains