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3 years ago

Unit rate of 12 in 4

Mathematics

1 answer:

Irina18 [472]3 years ago

4 0

Answer: 3

Step-by-step explanation:

i think im not 100% sure

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n 2000 the population of a small village was 2,400. With an annual growth rate of approximately 1.68%, compounded continuously,

Nitella [24]

Answer:

The population would be 3358

Step-by-step explanation:

Since, exponential growth function if the growth is compound continuously,

$A = Pe^{rt}$

Where,

P = initial population,

r = growth rate per period,

t = number of periods,

Given,

The population in 2000, P = 2,400,

Growth rate per year = 1.68% = 0.0168,

Number of years from 2000 to 2020, t = 20,

Thus, the population in 2020,

$A=2400 e^{0.0168\times 20}$

$=2400 e^{0.336}$

$= 3358.4136$

$\approx 3358$

6 0

3 years ago

A tunnel is built in form of a parabola. The width at the base of tunnel is 7 m. On

uysha [10]

Given:

The width at the base of parabolic tunnel is 7 m.

The ceiling 3 m from each end of the base there are light fixtures.

The height to light fixtures is 4 m.

To find:

Whether it is possible a trailer truck carrying cars is 4 m wide and 2.8 m high is going to drive through the tunnel.

Solution:

The width at the base of tunnel is 7 m.

Let the graph of the parabola intersect the x-axis at x=0 and x=7. It means x and (x-7) are the factors of the height function.

The function of height is:

$h(x)=ax(x-7)$ ...(i)

Where, a is a constant.

The ceiling 3 m from each end of the base there are light fixtures and the height to light fixtures is 4 m. It means the graph of height function passes through the point (3,4).

Putting x=3 and h(x)=4 in (i), we get

$4=a(3)((3)-7)$

$4=a(3)(-4)$

$\dfrac{4}{(3)(-4)}=a$

$-\dfrac{1}{3}=a$

Putting $a=-\dfrac{1}{3}$ , we get

$h(x)=-\dfrac{1}{3}x(x-7)$ ...(ii)

The center of the parabola is the midpoint of 0 and 7, i.e., 3.

The width of the truck is 4 m. If is passes through the center then the truck must m 2 m on the left side of the center and 2 m on the right side of the center.

2 m on the left side of the center is x=1.5.

A trailer truck carrying cars is 4 m wide and 2.8 m high is going to drive through the tunnel is possible if h(1.5) is greater than 2.8.

Putting x=1.5 in (ii), we get

$h(1.5)=-\dfrac{1}{3}(1.5)(1.5-7)$