A right rectangular prism has a volume of 40 cm^3. Find the new volume of the prism if only the length of the prism is doubled.

Question

A right rectangular prism has a volume of 40 cm^3.  Find the new volume of the prism if only the length of the prism is doubled.

triciaal · Answer

what is the formula for the volume of a rectangular prism?

bee_see · Answer

no picture? Volume of rectangular prism=(w)(l)(h). Here, 40=(w)(l)(h)

triciaal · Answer

let the length = l
Base area =l* w
double means 2 times 
if the length is doubled then the base area = (2l)* w

nightmarenight · Answer

@Bee_see no picture was attached to this question

triciaal · Answer

really don't need one

nightmarenight · Answer

(21)*w isn't an option o:

triciaal · Answer

important to see the formula  and see the change

triciaal · Answer

that was not the answer!!
that was for the new base area

triciaal · Answer

the volume for the prism = Bh where B is the base area and h is the height

nightmarenight · Answer

Ohhhh

triciaal · Answer

the area of the rectangle is l*w ; length * width
the new area = (2l)* w 
the new volume = new base area * height
  = (2l)*w*h

triciaal · Answer

now compare the old volume with the new volume to see the effective change with the change in only the length

nightmarenight · Answer

Oh it's B

triciaal · Answer

I have no idea . I did not see  the options. 
but do you see how to apply the formula?

nightmarenight · Answer

40cm^3

triciaal · Answer

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