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3 years ago

2. An elevator is on the twentieth floor. It goes down 11 floors and then up 5 floors.

Mathematics

1 answer:

Goryan [66]3 years ago

8 0

It is at the fourteenth floor

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Question 6 of 20

LuckyWell [14K]

Answer:

The answer is B

Step-by-step explanation:

It's just a matter of following the sequence

7 0

4 years ago

What is bigger 3/4 or 4/15?

Tems11 [23]

Answer:

3/4 is a bigger

Step-by-step explanation:

and 4/15 is a smaller

3 0

4 years ago

DO NOT OVERLOOK THIS!!!!!!!!

zmey [24]

<h2>Answer:</h2>

<u>Area</u> = 2(1/2 × 5 × 5) + 20 × 10

= 2 × 12.5 + 200

= 25 + 200

= 225ft².

3 0

3 years ago

The sum of the first 10 terms of an arithmetic sequence is 235 and the

Degger [83]

Answer:

$\bold{a_1 = -42.65}\\\\\bold{d=14.7}$

Step-by-step explanation:

The sum of the first 10 terms of an arithmetic sequence is:

$S_{10}=a_1+a_2+...+a_{10}=\dfrac{a_1+a_{10}}{2}\cdot10=\dfrac{2a_1+(10-1)d}{2}\cdot10$

$\dfrac{2a_1+(10-1)d}{2}\cdot10=235\\\\(2a_1+9d)\cdot5=235\\\\2a_2+9d=47$

the sum of the second 10 terms is: a₁₁ + a₁₂+...+ a₂₀

And the sum of the first 20 terms of an arithmetic sequence is:

$S_{20}=a_1+a_2+...+a_{10}+a_{11}+...+a_{20}=\dfrac{2a_1+(20-1)d}{2}\cdot10$

so the sum of the second 10 terms is:

$a_{11}+a_{12}+...+a_{20}=S_{20}-S_{10}$

Therefore we have:

$\dfrac{2a_1+(20-1)d}{2}\cdot10-\dfrac{2a_1+(10-1)d}{2}\cdot10=735\\\\(2a_1+19d)\cdot5-(2a_1+9d)\cdot5=735\\\\2a_1+19d-(2a_1+9d)=147\\\\10d=147\\\\d=14.7$

and:

$2a_1+9\cdot14.7=47\\\\2a_1+132.3=47\\\\2a_1=-85.3\\\\a_1=-42,65$

3 0

3 years ago

If the height of a cone is cut in half, the volume of the cone is multiplied by what number?

Assoli18 [71]

We know that
volume of a cone=(1/3)*pi*r²*h

<span>If the height of a cone is cut in half
so
h=h/2
and
new volume of a cone=</span>(1/3)*pi*r²*(h/2)----> (1/2)*[(1/3)*pi*r²*h)

the answer is
<span>the volume of the cone is multiplied by 1/2</span>

7 0

3 years ago