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1 year ago

A security alarm requires a four-digit code. The code can use the digits 0–9 and the digits cannot be repeated.

Mathematics

2 answers:

never [62]1 year ago

7 0

Answer:

The answer is <em>C</em>

Explanation: Given:A security alarm requires a four-digit code. The code can use the digits 0–9 and the digits cannot be repeated.

there is only 2 numbers which are greater than 7 i.e. 8 and 9. ∴ there is 2 possibility for first place.

For the remaining 3 digits there is 9 possibilities (including 1 which would left after choosing 1 from first place )

No of ways for the alarm code beginning with a number greater than 7= 2 P 1 x 9 P 3

<em>Total ways of code with 4 digits= 10 P 4.</em> Hope this helps :)

Oduvanchick [21]1 year ago

7 0

Answer: The answer is C

Step-by-step explanation:

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At a cafe, for every 5 sodas sold there are 9 teas sold. What is the ratio of teas sold to sodas sold? A) 5 : 9 B) 9 : 5 C) 9 :

frutty [35]

For 5 sodas sold, there are 9 teas sold

the ratio is tea: soda, or 9:5

B) 9:5 is your answer

hope this helps

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1 year ago

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Two families went to Rollercoaster World. The Brown family paid 170 for 3 children and 2 adults. The Peckham family paid 360 for

cestrela7 [59]

Answer: the system of equations are

3x + 2y = 170

4x + 6y = 360

Step-by-step explanation:

Let x represent the price of a child's ticket in dollars.

Let y represent the price of an adult's ticket in dollars.

The Brown family paid 170 for 3 children and 2 adults. This would be expressed as

3x + 2y = 170

The Peckham family paid 360 for 4 children and 6 adults. This would be expressed as

4x + 6y = 360

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1 year ago

Given: mTRV = 60° mTRS = (4x)° Prove: x = 30 What is the missing reason in step 3? substitution property of equality angle addit

mihalych1998 [28]

Answer: Angle addition postulate.

Explanation: If $\angle TRV= 60^{\circ}$ and $\angle TRS=4x^{\circ}$

here, if we have to prove x=30

If there is a condition that TR is a line which meets with the line segment VS at point R then by the Angle addition postulate, we can say that $\angle TRV+\angle TRS=180^{\circ}$ ⇒ $x=30^{\circ}$

But,

In option (1) substitution property of equality

If there is condition that $\angle TRV=\angle TRS$

then we can use substitution property of equality,

And, in this case $4x^{\circ}=60^{\circ}$ ⇒ $x=15^{\circ}$

which is wrong. So, we can not use this property here.

In option (3) subtraction property of equality

There is no use of this property to find the value x.

In option (4) addition property of equality

There is no use of this property to find the value x.

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1 year ago

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While starting salaries have fallen for college graduates in many of the top hiring fields, there is some good news for business

andriy [413]

Answer:

Step-by-step explanation:

According to the central limit theorem, if independent random samples of size n are repeatedly taken from any population and n is large, the distribution of the sample means will approach a normal distribution. The size of n should be greater than or equal to 30. Given n = 100 for both scenarios, we would apply the formula,

z = (x - µ)/(σ/√n)

a) x is a random variable representing the salaries of accounting graduates. We want to determine P( x > 52000)

From the information given

µ = 50402

σ = 6000

z = (52000 - 50402)/(6000/√100) = 2.66

Looking at the normal distribution table, the probability corresponding to the z score is 0.9961

b) x is a random variable representing the salaries of finance graduates. We want to determine P(x > 52000)

From the information given

µ = 49703

σ = 10000

z = (52000 - 49703)/(10000/√100) = 2.3

Looking at the normal distribution table, the probability corresponding to the z score is 0.9893

c) The probabilities of either jobs paying that amount is high and very close.

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1 year ago

What is a31 of the arithmetic sequence for which a5=12.4 and a9=22.4

miv72 [106K]

For the arithmetic sequence
a₁, a₂, a₃, ...,
the n-th term is
$a_{n}=a_{1}+(n-1)d$
where d = the common difference

Because a₅ = 12.4,
a₁ + 4d = 12.4 (1)
Because a₉ = 22.4,
a₁ + 8d = 22.4 (2)

Subtract (1) from (2).
a₁ + 8d - (a₁ + 4d) = 22.4 - 12.4
4d = 10
d = 2.5
From (1),
a₁ = 12.4 - 4*2.5 = 2.4

Therefore
a₃₁ = 2.4 + 30*2.5 = 77.4

Answer: a₃₁ = 77.4

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2 years ago