Question

The volume of a 10 ounce box of cheerios is 258.75in3. the length of the box is 4 inches less than the height and the width is 3 inches. determine the height of the box

Answer 1

Answer:

Height of the box = 11.5 in

Step-by-step explanation:

Let h be the height of the box.

Assuming the volume of the Box is $258.75\ in^3$.

Given:

Length = Height - 4 = h - 4

Width = 3 in

We need to find the height of the box.

Solution:

We know that the volume of the box.

$Volume = Length\times height\times width$

Substitute all given value in above formula.

$258.75 = (h-4)\times h\times 3$

Rewrite the equation as:

$258.75 = 3h(h-4)$

$258.75 = 3h^2-12h$

$3h^2-12h-258.75=0$

whole equation divided by 3.

$h^2-4h-86.25=0$

Use quadratic formula with $a = 1, b = -4,c=-86.25$

$h=\frac{-b\pm \sqrt{(b)^{2}-4ac}}{2a}$

Put these a, b and c value in above equation.

$h=\frac{-(-4)\pm \sqrt{(-4)^{2}-4(1)(-86.25)}}{2(1)}$

$h=\frac{4\pm \sqrt{16+345}}{2}$

$h=\frac{4\pm \sqrt{361}}{2}$

$h=\frac{4\pm 19}{2}$

For positive sign

$h=\frac{23}{2}$  

h = 11.5 in

For negative sign

$h=\frac{-15}{2}$

h = -7.5

We take positive value of h.

Therefore, the height of the box h = 11.5 in