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2 years ago

the sum of the digits of a certain two-digits number is 7.Reversing its digits increases the number by 9.What is the number

2 answers:

8 0

Unit digit=y
tens digit=x
the number: 10x+y

We suggest this system of equations:
x+y=7
(10y+x)=(10x+y)+9
we solve it by substitution method.
x=7-y
10y+(7-y)=(10(7-y)+y)+9
9y+7=70-10y+y+9
9y+10y-y=70+9-7
18y=72
y=72/18=4

x=7-y
x=7-4=3

number=10x+y=10*3+4=30+4=34

solution: the number: 34

To check:
3+4=7
43=34+9

dimaraw [331]2 years ago

7 0

The answer is 34. 3+4=7. 43-34=9. I hope this helps.

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HURRY 20 POINTS!!!!! Given the geometric sequence an = 6(5)n − 1, which of the following values for n lies in the appropriate do

Lapatulllka [165]

<h2>Answer:</h2>

n = 1

<h2>Explanation:</h2>

Here we have the following Geometric Sequence:

$a_{n} = 6(5)^{n-1}$

Where:

$a=6 \ \text{First term} \\ \\ r=5 \ \text{Common ratio} \\ \\ n: \ \text{Number of terms}$

The first term occurs when $n=1$ . Next the second term occurs when $n=2$ , the third term when $n=3$ and so on. Therefore, the appropriate value of n that lies on the domain for n is $n=1$

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2 years ago

Formula of perimeter and area

OverLord2011 [107]

Answer:

Perimeter: 4 * s

Area: S 2

Diagonal: s 2 \sqrt {2} 2

Area of square when diagonal is given = 1 2 × d 2 \frac {1} {2}\times d^ {2} 21 × d2

Step-by-step explanation:

5 0

1 year ago

Read 2 more answers

This is due today, and I have no idea what I'm doing, please help if you know anything.

defon

Binomial distribution formula: P(x) = (n k) p^k * (1 - p)^n - k

a) Probability that four parts are defective = 0.01374

P(4 defective) = (25 4) (0.04)^4 * (0.96)^21

P(4 defective) = 0.01374

b) Probability that at least one part is defective = 0.6396

Find the probability that 0 parts are defective and subtract that probability from 1.

P(0 defective) = (25 0) (0.04)^0 * (0.96)^25

P(0 defective) = 0.3604

1 - 0.3604 = 0.6396

c) Probability that 25 parts are defective = approximately 0

P(25 defective) = (25 25) (0.04)^25 * (0.96)^0

P(25 defective) = approximately 0

d) Probability that at most 1 part is defective = 0.7358

Find the probability that 0 and 1 parts are defective and add them together.

P(0 defective) = 0.3604 (from above)

P(1 defective) = (25 1) (0.04)^1 * (0.96)^24

P(1 defective) = 0.3754

P(at most 1 defective) = 0.3604 + 0.3754 = 0.7358

e) Mean = 1 | Standard Deviation = 0.9798

mean = n * p

mean = 25 * 0.04 = 1

stdev = $\sqrt{np(1-p)}$

stdev = $\sqrt{(25)(0.04)(1-0.04)}$ = 0.9798

Hope this helps!! :)

7 0

2 years ago

Find the value of annuity if the periodic deposit is $250 at 5% compounded quarterly for 10 years

mylen [45]

Answer:

The value of annuity is $P_v = \$ 7929.9$

Step-by-step explanation:

From the question we are told that

The periodic payment is $P = \$ 250$

The interest rate is $r = 5\% = 0.05$

Frequency at which it occurs in a year is n = 4 (quarterly )

The number of years is $t = 10 \ years$

The value of the annuity is mathematically represented as

$P_v = P * [1 - (1 + \frac{r}{n} )^{-t * n} ] * [\frac{(1 + \frac{r}{n} )}{ \frac{r}{n} } ]$ (reference EDUCBA website)

substituting values

$P_v = 250 * [1 - (1 + \frac{0.05}{4} )^{-10 * 4} ] * [\frac{(1 + \frac{0.05}{4} )}{ \frac{0.08}{4} } ]$

$P_v = 250 * [1 - (1.0125 )^{-40} ] * [\frac{(1.0125 )}{0.0125} ]$

$P_v = 250 * [0.3916 ] * [\frac{(1.0125)}{0.0125} ]$

$P_v = \$ 7929.9$

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2 years ago

Wilbur runs 3.2 km every morning how many feet are in 3.2 km given that 1 mile = 1.609 km and 1 mile = 5,280

Nonamiya [84]

1.609/5280 = 3.2/x....1.609 km to 5380 ft = 3.2 km to x ft
cross multiply because this is a proportion
(1.609)(x) = (5280)(3.2)
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x = 16896/1.609
x = 10,500 ft <===

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3 years ago

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