The original price of jeans is $32.

What is the probability of rolling a three on the first die and a two on the second die?

Neporo4naja [7]

The two rolls of the number cube are independent events because
the result of 1 roll does not affect the result of the other roll.
To find the probability of two independent events, we first find
the probability of each event, then we multiply the probabilities.
We can find the probability of an event using the following ratio:
number of favorable outcomes/total number of outcomes
Since there is only one way to roll a 3 and there are six
possible outcomes, 1, 2, 3, 4, 5, and 6, the probability of rolling a 3 is 1/6.
Since there is also only one way to roll a 2 and there are
six possible outcomes, the probability of rolling a 2 would be 1/6.
Now we multiply the probabilities.
1/6 x 1/6 is 1/36.
So the probability of rolling a 3 and a 2 is 1/36.

8 0

3 years ago

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What is true of a geometric straight line? A) one-dimensional B) two-dimensional C) three-dimensional D) no dimensions, only pos

Lubov Fominskaja [6]

A. the answer is one dimension

5 0

4 years ago

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Let C be the curve of intersection of the parabolic cylinder x^2 = 2y, and the surface 3z = xy. Find the exact length of C from

Maslowich

I've attached a plot of the intersection (highlighted in red) between the parabolic cylinder (orange) and the hyperbolic paraboloid (blue).

The arc length can be computed with a line integral, but first we'll need a parameterization for $C$ . This is easy enough to do. First fix any one variable. For convenience, choose $x$ .

Now, $x^2=2y\implies y=\dfrac{x^2}2$ , and $3z=xy\implies z=\dfrac{x^3}6$ . The intersection is thus parameterized by the vector-valued function

$\mathbf r(x)=\left\langle x,\dfrac{x^2}2,\dfrac{x^3}6\right\rangle$

where $0\le x\le 4$ . The arc length is computed with the integral

$\displaystyle\int_C\mathrm dS=\int_0^4\|\mathbf r'(x)\|\,\mathrm dx=\int_0^4\sqrt{x^2+\dfrac{x^4}4+\dfrac{x^6}{36}}\,\mathrm dx$

Some rewriting:

$\sqrt{x^2+\dfrac{x^4}4+\dfrac{x^6}{36}}=\sqrt{\dfrac{x^2}{36}}\sqrt{x^4+9x^2+36}=\dfrac x6\sqrt{x^4+9x^2+36}$

Complete the square to get

$x^4+9x^2+36=\left(x^2+\dfrac92\right)^2+\dfrac{63}4$

So in the integral, you can substitute $y=x^2+\dfrac92$ to get

$\displaystyle\frac16\int_0^4x\sqrt{\left(x^2+\frac92\right)^2+\frac{63}4}\,\mathrm dx=\frac1{12}\int_{9/2}^{41/2}\sqrt{y^2+\frac{63}4}\,\mathrm dy$

Next substitute $y=\dfrac{\sqrt{63}}2\tan z$ , so that the integral becomes

$\displaystyle\frac1{12}\int_{9/2}^{41/2}\sqrt{y^2+\frac{63}4}\,\mathrm dy=\frac{21}{16}\int_{\arctan(3/\sqrt7)}^{\arctan(41/(3\sqrt7))}\sec^3z\,\mathrm dz$

This is a fairly standard integral (it even has its own Wiki page, if you're not familiar with the derivation):

$\displaystyle\int\sec^3z\,\mathrm dz=\frac12\sec z\tan z+\frac12\ln|\sec x+\tan x|+C$

So the arc length is

$\displaystyle\frac{21}{32}\left(\sec z\tan z+\ln|\sec x+\tan x|\right)\bigg|_{z=\arctan(3/\sqrt7)}^{z=\arctan(41/(3\sqrt7))}=\frac{21}{32}\ln\left(\frac{41+4\sqrt{109}}{21}\right)+\frac{41\sqrt{109}}{24}-\frac98$

4 0

4 years ago

At the bake sale there were 40 raisin cookies sold. If ratio of raisin cookies sold to oatmeal cookies sold was 5:1 what is the

Annette [7]

Answer:

48 cookies were sold in total.

Step-by-step explanation:

5:1 is the ratio of raisin cookies to oatmeal cookies, and 40 raisin cookies were sold. Meaning, 40:?.

To find the number of oatmeal cookies you divide 40 by 5, which gets 8. This means that the original ratio is multiplied by 8 to get the current ratio for the amount if cookies. 5(8) : 1(8) = 40:8. There are 40 raisin cookies and 8 oatmeal cookies. 40+8=48. There were 48 cookies sold in total.

6 0

3 years ago

Jenny and her 4 friends went out to dinner on Tuesday night. The total dinner bill was $110.00. The girls would like to leave a

sveta [45]

Answer:

$129.8

Step-by-step explanation:

Well, 18% of $110.00 dollars would be 19.8.

We get this by multiplying: 110.00 x 0.18 = 19.8.

We then add $19.8 to $110.00 and then the total would be $129.8.

3 0

3 years ago