Rectangular prism that has a surface area of 158 square yards

You are constructing a cardboard box from a piece of cardboard with the dimensions 2 m by 4 m. You then cut equal-size squares f

postnew [5]

Answer:

Dimensions:

l =3,15 m

w=1,15 m

x= 0,42 m (height)

V(max) = 1,52 m³

Step-by-step explanation:

The cardboard is L = 4 m and W = 2 m

Let call x the length of the square to cut in each corner, then, volume of open box is:

For the side L is L - 2*x l = 4 - 2*x

For the side W is W - 2*x w= 2 - 2*x

The height is x

Volume of the open box, as function of x is:

V(x) = ( 4 -2x) * ( 2 - 2x) *x ⇒ V(x) = ( 8 - 8x -4x + 4x²) *x

V(x) = ( 8 -12x + 4x² )*x V(x) = 8x - 12x² + 4x³

V(x) = 8x - 12x² + 4x³

Taking derivatives on both sides of the equation

V´(x) = 8 - 24x + 12x²

V´(x) = 0 8 - 24x + 12x² = 0 reordering 12x² - 24x + 8 = 0

or 3x² - 6x + 2 = 0

A second degree equation. Solving for x

x₁,₂ = ( 6 ± √36 - 24 ) /6

x₁,₂ = ( 6 ± 3.46) /6

x₁ = 6 + 3,46 /6 x₁ = 1.58 we dismiss such solution because 1,58 * 2 = 3,15 and is bigger than 2 one of the side of the cardboard

x₂ =( 6 - 3,46 ) / 6

x₂ = 0,42 m

Dimensions of the open box

l = 4 - 2*x l = 4 - 0,85 l = 3,15 m

w = 2 -2*x w = 2 - 0,85 w = 1,15 m

x = 0,42 m

V(max) =3,15*1,15*0,42

V(max) = 1,52 m³

8 0

3 years ago

There is a bag filled with 5 blue and 6 red marbles.

Afina-wow [57]

Answer:

The probability of getting two of the same color is 61/121 or about 50.41%.

Step-by-step explanation:

The bag is filled with five blue marbles and six red marbles.

And we want to find the probability of getting two of the same color.

If we're getting two of the same color, this means that we are either getting Red - Red or Blue - Blue.

In other words, we can find the independent probability of each case and add the probabilities together*.

The probability of getting a red marble first is:

$\displaystyle P\left(\text{Red}\right)=\frac{6}{11}$

Since the marble is replaced, the probability of getting another red is: $\displaystyle P\left(\text{Red, Red}\right)=\frac{6}{11}\cdot \frac{6}{11}=\frac{36}{121}$

The probability of getting a blue marble first is:

$\displaystyle P\left(\text{Blue}\right)=\frac{5}{11}$

And the probability of getting another blue is:

$\displaystyle P\left(\text{Blue, Blue}\right)=\frac{5}{11}\cdot \frac{5}{11}=\frac{25}{121}$

So, the probability of getting two of the same color is:

$\displaystyle P(\text{Same})=\frac{36}{121}+\frac{25}{121}=\frac{61}{121}\approx50.41\%$

*Note:

We can only add the probabilities together because the event is mutually exclusive. That is, a red marble is a red marble and a blue marble is a blue marble: a marble cannot be both red and blue simultaneously.

4 0

2 years ago

5 boys were to carry a load of 2½kg. They shared the load equally. What is the weight of load carried by each boy?

mr Goodwill [35]

Answer:

1/2 or 0.5 kg

Step-by-step explanation:

This is a division problem.

See attached.