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3 years ago

Plz I need help with some Maths?

Mathematics

1 answer:

Dima020 [189]3 years ago

3 0

Before Brian starts messing with them, there are 24 balls in the bag.
9 of them are white.

-- The probability that Brian draws a white ball from the bag is (9/24) .

If he has already drawn one white ball and put it aside, then there are
23 balls left in the bag, and 8 of them are white.

-- The probability that Brian draws a white ball from the bag this time
is (8/23) .

So the probability of white balls on both draws is

   (9/24) x (8/23) =

      (72/552) =

   3 / 23 = about <em>13% </em>(rounded)

You might be interested in

Use the shell method to write and evaluate the definite integral that represents the volume of the solid generated by revolving

harina [27]

Answer:

The volume of the solid is 714.887 units³

Step-by-step explanation:

* Lets talk about the shell method

- The shell method is to finding the volume by decomposing

a solid of revolution into cylindrical shells

- Consider a region in the plane that is divided into thin vertical

rectangle

- If each vertical rectangle is revolved about the y-axis, we

obtain a cylindrical shell, with the top and bottom removed.

- The resulting volume of the cylindrical shell is the surface area

of the cylinder times the thickness of the cylinder

- The formula for the volume will be: V = $\int\limits^a_b {2\pi xf(x)} \, dx$ ,

where 2πx · f(x) is the surface area of the cylinder shell and

dx is its thickness

* Lets solve the problem

∵ y = $x^{\frac{5}{2}}$

∵ The plane region is revolving about the y-axis

∵ y = 32 and x = 0

- Lets find the volume by the shell method

- The definite integral are x = 0 and the value of x when y = 32

- Lets find the value of x when y = 0

∵ $y = x^{\frac{5}{2}}$

∵ y = 32

∴ $32=x^{\frac{5}{2}}$

- We will use this rule to find x, if $x^{\frac{a}{b}}=c, then=== x=c^{\frac{b}{a}}$ , where c

is a constant

∴ $x=(32)^{\frac{2}{5}}=4$

∴ The definite integral are x = 0 , x = 4

- Now we will use the rule

∵ $V = \int\limits^a_b {2\pi}xf(x) \, dx$

∵ y = f(x) = x^(5/2) , a = 4 , b = 0

∴ $V=2\pi \int\limits^4_0 {x}.x^{\frac{5}{2}}\, dx$

- simplify x(x^5/2) by adding their power

∴ $V = 2\pi \int\limits^4_0 {x^{\frac{7}{2}}} \, dx$

- The rule of integration of $x^{n} is ==== \frac{x^{n+1}}{(n+1)}$

∴ $V = 2\pi \int\limits^4_0 {x^{\frac{9}{2}}} \, dx=2\pi[\frac{x^{\frac{9}{2}}}{\frac{9}{2}}]$ from x = 0 to x = 4

∴ $V=2\pi[\frac{2}{9}x^{\frac{9}{2}}]$ from x = 0 to x = 4

- Substitute x = 4 and x = 0

∴ $V=2\pi[\frac{2}{9}(4)^{\frac{9}{2}}-\frac{2}{9}(0)^{\frac{9}{2}}}]=2\pi[\frac{1024}{9}-0]$

∴ $V=\frac{2048}{9}\pi=714.887$

* The volume of the solid is 714.887 units³

5 0

3 years ago

I don't quite understand the LCD and the unlike denominators properly. May someone explain it, please.

Whitepunk [10]

Hey!

----------------------------------------------------------------------

LCD stands for Lowest Common Denominator.

----------------------------------------------------------------------

Explanation:

So let's say we have the equation 1/9 * 16/27

We want to find the LCD of both fractions. To find the LCD of both fractions find a the lowest common denominator in both fractions.

In this equation the lowest common denominator is 27 because 9 can go in 27 and 27 can go into itself. Se basically 27 is the lowest possibly common denominator both fractions can get to.

----------------------------------------------------------------------

Hope This Helped! Good Luck ;)

5 0

3 years ago

What is the probability that the first card is a kingking and the second card is a kingking if the sampling is done with replac

IRINA_888 [86]

You want to draw 2 kings from a 52 card deck. And you do it with replacement.
There are 4 kings in a standard deck. The probability of getting one of them is
4/52 on the first draw.

For the second draw the probability is the same.
4/52

The probability for both happening is
(4/52)*(4/52) = (1/13)*(1/13) = 1/169 = 0.001597

5 0

4 years ago

One light year is 5.8697136 x 10^12 miles. How for is 8.333 light minutes?

kirill115 [55]

Work out length of one second by dividing by 525600, then multiply that answer by 8.333. Answer should be 93026473.1507 miles

5 0

3 years ago

This is a linear equation/ graph quiz ! please help , my teacher makes no sense to me!

JulijaS [17]

Answer:

(8,5)

Step-by-step explanation:

5x - 2y = 30

coordinates are (x,y) so you plug in 8 for x and solve for y

5(8) - 2y = 30

40 - 2y = 30

subtract 40 from both sides to isolate y

-2y = -10

divide both sides by -2 to isolate y

y = 5

6 0

3 years ago

Read 2 more answers