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Ray Of Light [21]
2 years ago
14

35. the set, s consists of 900,000,000 whole numbers, each being the same number of digits long. howmany digits long is a number

from s? (hint: use the fact that a whole number cannot start with the digit 0.)
Mathematics
1 answer:
weeeeeb [17]2 years ago
4 0

Answer:

  • 9 digit long

Let the number of digits be n and the number of elements in set be s.

<h3>When n = 1</h3>
  • The set contains 1-digit numbers, 1 through 9,
  • The set consists of 10 - 1 = 9 numbers.

<h3>When n = 2</h3>
  • The set contains 2-digit numbers, 10 through 99,
  • The set contains 100 - 10 = 90 numbers.

<h3>When n = 3</h3>
  • The set contains 3-digit numbers, 100 through 999,
  • The set contains 1000 - 100 = 900 numbers.

The pattern we see helps us determine the relationship between s and n as follows.

When set contains n-digit numbers, the set contains:

  • s = 10ⁿ - 10ⁿ⁻¹ = 10ⁿ⁻¹(10 - 1) = 9*10ⁿ⁻¹ elements

We have s known, substitute it into equation above and solve for n:

  • 900000000 = 9*10ⁿ¹
  • 100000000 = 10ⁿ⁻¹
  • 10⁸ = 10ⁿ⁻¹
  • n - 1 = 8
  • n = 9

The numbers in the set s are 9-digit long.

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a sheep breeding farm counted a total of 40 sheep on their grounds after one year the number of sheep doubled then in the next y
SpyIntel [72]
Answer:
graph (b)

Explanation:
The farm started with 40 sheep and the number doubled each year.
So, the equation modeling this situation would be:
N(x) = 40*(2)^2
By getting the equation, we can notice that we already excluded the third and fourth choices as they have the wrong equations.

Now, we will need to select the right graph which is either graph a or graph b.
To do this, we will get the value of N(x) for different values of x as follows:
At x = 0: N(0) = 40*(2)^0 = 40
At x = 1: N(1) = 40*(2)^1 = 80
At x = 1: N(2) = 40*(2)^2 = 160

Now, taking a look at graph a, we will find that:
N(1) = 120
N(2) = 360
These numbers are not the same as the numbers we calculated, therefore, this graph is wrong

Taking a look at graph b, we will find that:
N(1) = 80
N(2) = 160
These numbers are exactly the same as the ones calculated, therefore, this graph is the correct one.

Hope this helps :)
7 0
4 years ago
If 2a = 3 + 2b, prove that 8a3 – 8b3 – 36ab = 27.
irga5000 [103]

b = -0.5 and a = 1. 2=3+-1. 1 to the third power is just 1, times 8 is 8. -0.5 to the third power is -0.125. -0.125 times 8 is -1. 8 - (-1) is 9. 36 times 1 is 36, times -0.5 is -18. 9-(-18) = 27. I hope this helps! Could I possibly get brainliest?

3 0
3 years ago
The sum of three consecutive odd numbers is one hundred fifty-nine
xeze [42]
First remember that sum means to add. now think about the equation. we need to find 3 numbers that equal 159 when added together. And they are all consecutive odd numbers. so let's call the first number X. the second number would be X+2 since we have to jump over 1 even number. The third number would be X+4 since we have to jump over 2 even numbers. so now an equation to represent this would be X+(X+2)+(X+4)=159. Add like terms, and remember order of operations. if you need help getting the answers leave me a comment.
8 0
3 years ago
Suppose your statistics professor reports test grades as​ z-scores, and you got a score of 2.492.49 on an exam. ​a) Write a sent
kolezko [41]

Answer:

a) Option C) The score was 2.49 standard deviations higher than the mean score in the class.

b) 2.3%

Step-by-step explanation:

a) We are given that the distribution of test grades is a bell shaped distribution that is a normal distribution.

Formula:

z_{score} = \displaystyle\frac{x-\mu}{\sigma}

\displaystyle\frac{x-\mu}{\sigma} = 2.49\\\\x - \mu = 2.49\sigma\\x = \mu + 2.49\sigma

Option C) The score was 2.49 standard deviations higher than the mean score in the class.

b) The z-score for a particular score is -2.

We have to evaluate

P(z < -2)

Calculating the value from normal z-table.

P(z < -2) = 0.023

Thus, 2.3% of  of the class scored lower than my​ friend.

6 0
3 years ago
Please put answer as a mixed number! :)<br> 1 and 3/8* 1.5 + 5 and 5/8 ÷ 0.4 =
Natasha_Volkova [10]

Answer: 7 1/16  and 1 9/16

Step-by-step explanation:  1 3/8 x 1.5 is 1 3/8 x 1 5/10  11/8 x 15/10 which is 165/80. We divide it by 5/5 to get 33/16. This as a mixed number is 2 1/16.  We add 5 to get 7 1/16.

5/8 divided by 0.4 is 5/8 divided by 2/5. We divide this by first finding the reciprocal of 2/5 which is 5/2. 5/8 x 5/2 = 25/16. This as a mixed number is 1 9/16.

8 0
2 years ago
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