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Alexxx [7]
3 years ago
9

How many two digit numbers do not contain the digit 9?

Mathematics
1 answer:
cricket20 [7]3 years ago
5 0
87 numbers do not contain the digit 9
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How i get the y-intercept
jeka94

Answer:

<em>hey </em>

Step-by-step explanation:

which u r studying inn

5 0
2 years ago
There are 210210210 students in a twelfth grade high school class. 909090 of these students have at least one sister and 1051051
BlackZzzverrR [31]

Answer:

(1) The value of P (A) is 0.4286.

(2) The value of P (B) is 0.50.

(3) The value of P (A ∩ B) is 0.2143.

(4) The the value of P (B|A) is 0.50.

(5) The events <em>A</em> and <em>B</em> are independent.

Step-by-step explanation:

The events are defined as follows:

<em>A</em> = a student in the class has a sister

<em>B</em> = a student has a brother

The information provided is:

<em>N</em> = 210

n (A) = 90

n (B) = 105

n (A ∩ B) = 45

The probability of an event <em>E</em> is the ratio of the favorable number of outcomes to the total number of outcomes.

P(E)=\frac{n(E)}{N}

The conditional probability of an event <em>X</em> provided that another event <em>Y</em> has already occurred is:

P(X|Y)=\frac{P(A\cap Y)}{P(Y)}

If the events <em>X</em> and <em>Y</em> are independent then,

P(X|Y)=P(X)

(1)

Compute the probability of event <em>A</em> as follows:

P(A)=\frac{n(A)}{N}\\\\=\frac{90}{210}\\\\=0.4286

The value of P (A) is 0.4286.

(2)

Compute the probability of event <em>B</em> as follows:

P(B)=\frac{n(B)}{N}\\\\=\frac{105}{210}\\\\=0.50

The value of P (B) is 0.50.

(3)

Compute the probability of event <em>A</em> and <em>B</em> as follows:

P(A\cap B)=\frac{n(A\cap B)}{N}\\\\=\frac{45}{210}\\\\=0.2143

The value of P (A ∩ B) is 0.2143.

(4)

Compute the probability of <em>B</em> given <em>A</em> as follows:

P(B|A)=\frac{P(A\cap B)}{P(A)}\\\\=\frac{0.2143}{0.4286}\\\\=0.50

The the value of P (B|A) is 0.50.

(5)

The value of P (B|A) = 0.50 = P (B).

Thus, the events <em>A</em> and <em>B</em> are independent.

6 0
4 years ago
Given the sequence, 26, 13, 6.5, ..... find a) the 10th term and b) the sum of the first 18 terms
Hunter-Best [27]

Answer:

a) 10th term is 0.051

b) The sum of first 18 terms of given sequence is 51.48

Step-by-step explanation:

We are given the sequence 26, 13, 6.5, ..... we need to find

a) 10th term

b) Sum of first 18 terms

Before solving we need to determine if the sequence is arithmetic or geometric

The sequence is arithmetic if common difference d is same.

The sequence is geometric if common ratio r is same.

Finding common difference d: 13-26 = -13, 6.5-13= -6.5

As common difference is not same so, the sequence is not arithmetic.

Finding common ratio r : 13/26 =0.5, 6.5/13= 0.5

As common ratio is same so, the sequence is geometric.

a) Finding common difference: 13-26 = -13, 6.5-13= -6.5

As common difference is not same so, the sequence is not arithmetic.

a) 10th term

The formula to find 10th term is: a_n=a_1r^{n-1}

We have a₁=26 and r = 0.5 n=10

a_n=a_1r^{n-1}\\a_{10}=26(0.5)^{10-1}\\a_{10}=26(0.5)^{9}\\a_{10}=0.051

So, 10th term is 0.051

b) Sum of first 18 terms

The formula to find sum of geometric series is: S_n=\frac{a(1-r^n)}{1-r}

where a= 1st term, r = common ratio and n= number of terms

In the given sequence we have

a=26, r=0.5 and n=18

Finding sum of first 18 terms

S_n=\frac{a(1-r^n)}{1-r}\\S_{18}=\frac{26(1-(0.5)^{18}}{1-0.5}\\S_{18}=\frac{26(0.99)}{0.5}\\S_{18}=\frac{25.74}{0.5}\\S_{18}=51.48

So, sum of first 18 terms of given sequence is 51.48

6 0
3 years ago
A force F1 of magnitude 6.00 units acts at the origin in a direction 30.0 above the positive x axis. A second force F2 of magnit
kumpel [21]
F1 = 6*cos(30) i + 6*sin(30) j = 5.20 i + 3 j 
<span>F2 = 0 i + 5 j </span>

<span>R = F1 + F2 </span>
<span>Add the 'i's together (x direction) and the 'j's together (y direction) </span>
<span>R = (5.20 + 0) i + (3 + 5) j = 5.2 i + 8 j </span>

<span>Magnitude: </span>
<span>||R|| = </span>√<span>(5.2^2 + 8 ^2) = </span>√<span>91 = 9.54 </span>

<span>Direction: </span>
Θ<span> = atan ( Rj / Ri ) = atan( 8 / 5.2 ) = 57.0</span>⁰
5 0
3 years ago
PLEASE HELP this is due soon, I will mark brainliest if I can.
I am Lyosha [343]

Answer:

  • 102 cm

Step-by-step explanation:

  • Diagonals of a rhombus are perpendicular.
  • Sides are of equal length.

<u>Use Pythagorean to work out the side length.</u>

  • a² = (d₁/2)² + (d₂/2)²
  • a² = (24/2)² + (45/2)² = 650.25
  • a = √650.25
  • a = 25.5 cm

<u>The perimeter is:</u>

  • P = 4a
  • P = 4*25.5 = 102 cm
6 0
3 years ago
Read 2 more answers
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