Question

A box with no top is to be constructed from a piece of cardboard whose length measures 12 inches more than its width. The box is formed by cutting squares that measure 4 inch on each side from the four corners and then folding up the sides. If the volume of the box 256 in cm^3 what are the dimensions of the piece of cardboard? The Height? The width?

Answer 1

Answer:

Width is 12 inches and height is 4 inches.

Step-by-step explanation:

Let the width of the piece of cardboard be = w inches

Then length is = $w+12$ inches

As given, 4 inch squares are cut from each corner;

So, the width is = $w-8$ inches

Length is = $w+12-8=w+4$ inches

When we are folding the cut portion, that gives the height as = 4 inches

The volume is given by : length x width x height

And volume is given as 256 cubic inches

So, $256=(w+4)(w-8)(4)$

=> $256=(w^{2}-4w-32)4$

=> $64=(w^{2}-4w-32)$

=> $w^{2} -4w=96$

or $w^{2} -4w-96=0$

=> $w^{2} -12w+8w-96=0$

=> $w(w-12)+8(w-12)=0$

We get , $(w+8)=0$ ; w = -8(neglect the negative value)

$(w-12)=0$ ; w = 12 inches

And length = $12+12=24$ inches

Hence, dimensions are : L = 24 inches ; w = 12 inches and h = 4 inches

We can check by putting these values in equation : $256=(w+4)(w-8)(4)$

$256=(12+4)(12-8)(4)$

=> $256=(16)(4)(4)$

=> $256=256$