A certain square pyramid has a volume of 100 cm^3. A similar but smaller pyramid has a surface area equal to one fifth of the larger. What is the volume of the smaller pyramid?

1 Answer
Feb 13, 2018

"volume "=4sqrt5~~8.944" cubic cm"

Explanation:

"consider 2 similar figures then"

"linear ratios "=a:b

"area ratios "=a^2:b^2

"volume ratios "=a^3:b^3

"here "a^2:b^2=1:5

rArra:b=sqrt1:sqrt5=1:sqrt5

rArra^3:b^3=1^3:(sqrt5)^3=1:5sqrt5

rArr"volume of smaller pyramid "=100/(5sqrt5)

rArr"volume "=20/sqrt5xxsqrt5/sqrt5=4sqrt5" cubic cm"