Question

A pyramid has a height of 5 in. and a surface area of 90 in2. Find the surface area of a similar pyramid with a height of 10 in. Round to the nearest tenth, if necessary. (1 point)
360 in2
180 in2
22.5 in2
3.6 in2

Answer 1

This is just a proportion problem:

\[\frac{ 5 }{ 90 } = \frac{ 10 }{ x } \rightarrow 5x = 900 \rightarrow x=\frac{ 900 }{ 5 }\]

Answer 2

So SA = 180 in^2 for a height of 10.

Answer 3

thanks. do you know this A rectangular prism has a width of 92 ft and a volume of 240 ft2. Find the volume of a similar prism with a width of 23 ft. Round to the nearest tenth, if necessary. (1 point)
3.8 ft3
60 ft3
15 ft3
10.4 ft3

Answer 4

So basically it's another proportion:

\[\frac{ 92 }{ 240 } = \frac{ 23 }{ X }\]

Solve for x to get the ans.

Answer 5

D( x )

x = 0

x = 0

x = 0

x in (-oo:0) U (0:+oo)

92/240 = 23/x // - 23/x

92/240-(23/x) = 0

92/240-23*x^-1 = 0

-23*x^-1 = -23/60 // : -23

x^-1 = 1/60

-1 < 0

1/(x^1) = 1/60 // * x^1

1 = 1/60*x^1 // : 1/60

60 = x^1

x = 60

x = 60