All categories

3 years ago

Thuy rolls a number cube 7 times. which expression represents the probability of rolling a 4 exactly 2 times?

2 answers:

6 0

The result of rolling a number cube 7 times is a 7-digit number composed of digits 1,2,3,4,5 and 6 so that digits can repeat. The total number of possibilities is 6^7.

The number of possibilities where 4 appears exactly two times is 5^5*(7!-6!/2).
5^5 is the number of 5-digits numbers composed of digits 1,2,3,5 and 6 so that digits can repeat.
7! is the number of permutations of digits 1,2,3,4,4,5 and 6.
6! is the number of permutations of digits 1,2,3,{4,4},5 and 6.
We don't want to subtract all numbers where digits 4 appear side by side. That's why we must divide 6! by 2.

Finally, the probability is P=5^5(7!-6!/2)/7^7

mel-nik [20]3 years ago

5 0

Answer:

The answer is C I just took the test!!!!!!!

Step-by-step explanation:

You might be interested in

The equation y−5=−2(x−3) is in point-slope form. Which shows this equation in slope-intercept form?

MAXImum [283]

y - 5 = -2(x - 3)

Distribute -2.

y - 5 = -2x + 6

Add 5 to both sides.

y = -2x + 11

B) y = -2x + 11

4 0

3 years ago

Find the approximate area of a triangle that has vertices at A(-4,2),B(6,4)C(3,-1)

MrMuchimi

$area \: of \: triangle \: = \frac{1}{2} |( - 16) - (22)|$
$= \frac{1}{2} | - 44|$
$= | - 22|$
$area \: of \: triangle \: = 22$

6 0

3 years ago

Mr eliot is extremely careful with his money. He recently invested part of his $150,000 life savings in gold bullion and the res

DIA [1.3K]

Answer:

The amount invested in gold bullion by Mr. Eliot = $50,000

Step-by-step explanation:

Total amount of savings Me. Eliot ha s = $150,000

Let us assume the amount invested in gold bullion = $m

So, the amount invested in bank = $150,000 - m

Now, 5% on m = $\frac{5}{100} \times m = 0.05 m$

So, the profit in gold bullion = 0.05 m

and 3% on (150,000 -m) = $\frac{3}{100} \times (150,000 -m) = 0.03 (150,000 -m)$

= 4,500 - 0.03 m

So, the profit in bank = 4,500 - 0.03 m

Now, the total profit = $5,500

⇒Profit from gold bullion + ban = $5,500

⇒0.05 m + 4,500 - 0.03 m = $5,500

or, 0.02 m = 1000

⇒ m = 1000/0.02 = 50,000

Hence, the amount invested in gold bullion = m = $50,000

3 0

3 years ago

In a triangle ABC, measure of angle B is 90 degrees. AB is 3x-2 units and BC is x+3. If the area of the triangle is 17 sq cm, fo

Scorpion4ik [409]

Answer:

$x=\frac{8}{3}\ cm$

Step-by-step explanation:

we know that

The area of the right triangle ABC is equal to

$A=\frac{1}{2}(AB)(BC)$

we have

$A=17\ cm^2$

$AB=(3x-2)\ cm$

$BC=(x+3)\ cm$

substitute the values

$17=\frac{1}{2}(3x-2)(x+3)$

$34=(3x-2)(x+3)$

$34=3x^2+9x-2x-6$

$3x^2+7x-6-34=0$

$3x^2+7x-40=0$

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$3x^2+7x-40=0$

$a=3\\b=7\\c=-40$

substitute in the formula

$x=\frac{-7(+/-)\sqrt{7^{2}-4(3)(-40)}} {2(3)}$

$x=\frac{-7(+/-)\sqrt{529}} {6}$

$x=\frac{-7(+/-)23} {6}$

$x=\frac{-7(+)23} {6}=\frac{16}{6}=\frac{8}{3}$

$x=\frac{-7(-)23} {6}=-5$

therefore

The solution is

$x=\frac{8}{3}\ cm$

6 0

3 years ago

What transformation was not done to the linear parent function, f(x) = x, to

Butoxors [25]

Answer:

Step-by-step explanation:

The function shifted <em>left</em> five units instead of <em>right</em> five units.

There's no vertical compression in the equation provided, but that's probably just a typo since there's a random bracket that I assume was supposed to be a fraction.

7 0

2 years ago