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3 years ago

I need to know this ASAP 20 points,

Mathematics

2 answers:

Sonbull [250]3 years ago

7 0

Answer: B

Step-by-step explanation:

grigory [225]3 years ago

3 0

I think the answer is B

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What is adaptation?plz answer

mariarad [96]

Answer:

the action or process of adapting or being adapted

Step-by-step explanation:

In evolutionary theory, adaptation is the biological mechanism by which organisms adjust to new environments or to changes in their current environment. ... The idea of natural selection is that traits that can be passed down allow organisms to adapt to the environment better than other organisms of the same species

8 0

3 years ago

Read 2 more answers

Pls show full working out

sweet-ann [11.9K]

Answer:

Question 1a. i) $x=1.8m$

Question 1a. ii) $Volume=27.6m^3$

Question 1b) $Volume=65.9m^3$

Explanation:

Question 1 a. i) Find the value of x.

$tan(\theta )=\dfrac{opposite\text{ }leg}{adjacent\text{ }leg}$

For the smalll triangle you can write:

$tan(\theta )=\dfrac{x}{1m}$

For tthe big triangle:

$tan(\theta )=\dfrac{x+2.7m}{2.5m}$

Substitute:

$\dfrac{x}{1m}=\dfrac{x+2.7m}{2.5m}$

Solve for x:

$2.5x=x+2.7m\\\\2.5x-x=2.7m\\\\1.5x=2.7m\\\\x=2.7m/1.5\\\\x=1.8m$

Question 1a ii) Find the volume of the frustrum

Find the volume of a cone with height = 2.7m + 1.8m = 4.5m, and radius = 2.5m

Formula:

$Volume=(1/3)\pi \times radius^2\times height$

Substitute:

$Volume=(1/3)\pi \times (2.5m)^2\times 4.5m=9.375\pi m^3$

Find the volume of a cone with heigth = 1.8m and radius = 1m

$Volume=(1/3)\pi \times (1m)^2\times 1.8m=0.6\pi m^3$

Subtract the volume of the small cone from the volume of the big cone

$Volume\text{ }of\text{ }frustrum=9.375\pi m^3-0.6\pi m^3=8.775\pi m^3\approx 27.6m^3$

Question 1b. Calculate the volume of the bin

i) Upper frustrum

This is the same frustrum from the equation of above, thus ist volume is 27.6m³.

ii) Lower frustrum

$\dfrac{x}{2.0m}=\dfrac{x+2.4m}{2.5m}$

$2.5x=2(x+2.4m)\\\\2.5x=2x+4.8m\\\\0.5x=4.8m\\\\x=9.6m$

$Volume=(1/3)\pi \times (2.5m)^2\times (9.6m+2.4m)-(2.0m)^2\times (9.6m)$

$Volume=38.3m^3$

iii) Add the volume of the two frustrums

$Volume=27.6m^3+38.3m^3=65.9m^3$

6 0

3 years ago

-18 + 2a = 2(3a + 1)

Nadusha1986 [10]

Answer:

a = -5

Step-by-step explanation:

Given

-18 + 2a = 2(3a + 1)

Expand the bracket on the right

-18 + 2a = 2 x 3a + 2 x 1

-18 + 2a = 6a + 2

Add 18 to both sides

-18 + 18 + 2a = 6a + 2 + 18

2a = 6a + 20

Subtract 6a from both sides

2a - 6a = 6a - 6a + 20

-4a = 20

Divide both sides by -4

-4a/-4 = 20/-4

a = -5

3 0

3 years ago

Mrs. Shoelady gave her children $2.40 in quarters, dimes, and nickles. The number of nickles was twice the number of quarters. T

PilotLPTM [1.2K]

Answer:

6 quarters, 3 dimes, and 12 nickles

Step-by-step explanation:

Let's say Q is the number of quarters, D is the number of dimes, and N is the number of nickles.

From the information in the problem, we can write three equations:

25Q + 10D + 5N = 240

N = 2Q

Q = 2D

Solve the system of equations using substitution.

25(2D) + 10D + 5(2Q) = 240

50D + 10D + 10Q = 240

60D + 10(2D) = 240

60D + 20D = 240

80D = 240

D = 3

Q = 6

N = 12

There are 6 quarters, 3 dimes, and 12 nickles.

7 0

3 years ago

there are 420 birch trees, 160 oak trees and 300 wild trees, what percentage of the trees an oak tree

Vladimir79 [104]

Answer:

18,(18)%

Step-by-step explanation:

420 + 160 + 300 = 880 total trees

160 / 880 * 100% = 18,(18)%

7 0

3 years ago

Read 2 more answers