Plz help me I've been stuck on this

Andrew has a cell phone plan that provides 300 free minutes each month for

Mekhanik [1.2K]

Answer:

Andrew has a cell phone plan that provides 300 free minutes each month for a flat rate of $19. For any minutes over 300, Andrew is charged $0.39 per minute. Let x be the number of minutes Andrew uses per month and f(x) be the charges based on Andrew's cell phone plan. If then If then first 300 minutes are free and each minute of next (x-300) minutes costs $0.39, therefore Hence, { 19 + 0.39(x - 300), x > 300

Hoped I helped

4 0

3 years ago

A survey found that 8 out of 10 parents approved of the new principal’s performance. If 4 parents name are chosen with replaceme

Natasha2012 [34]

Answer:

The probability is 0.044

Step-by-step explanation:

Step-by-step explanation:

Let p be the probability that the new principal’s performance is approved.

This is obtainable from the survey and it is 8/10 = 0.8

Let q be the probability that the new principal’s performance is disproved.

That will be;

1 - q = 1- 0.8 = 0.2

To calculate the probability that 14 parents names are chosen at random and they all

approve of the principal’s performance, we use the Bernoulli approximation of the binomial theorem.

That will be;

14C14 * p^14 * q^0

= 1 * 0.8^14 * 0.2^0

= 0.043980465111 which is approximately 0.044

8 0

3 years ago

A source of laser light sends rays AB and AC toward two opposite walls of a hall. The light rays strike the walls at points B an

Nataly [62]

Answer:

The distance between the walls is 70 m.

Step-by-step explanation:

Given: A source of laser light is at point A on the ground between two parallel walls BE and CD . The walls are perpendicular to the ground that is

BE ⊥ ED and CD ⊥ ED

AB is a ray of light which strikes the wall on the left at point B which is 30 meters above the ground. that is BE = 30 m

AC is a ray of light which strikes the wall on the right at point C. The length of AC = 80 meters.

The ray AB makes an angle of 45 degrees with the ground that is m∠BAE = 45°

The ray AC makes an angle of 60 degrees with the ground that is m∠CAD = 60°

As shown is figure attached below.

WE have to find the distance between the walls that is Length of ED

Length of ED = EA + AD

Consider the Δ AEB,

Using trigonometric ratio,

$\tan\theta=\frac{perpendicular}{base}$

Here $\theta=45^{\circ}$ , perpendicular = 30 m and base we can find.

thus,

$\tan 45^{\circ}=\frac{30}{EA}$

We know $\tan 45^{\circ}=1$

thus, EA = 30 m

Consider the Δ AEB,

Using trigonometric ratio,

$\cos\theta=\frac{base}{hypotenuse}$

Here $\theta=60^{\circ}$ , hypotenuse = 80 m and base we can find.

thus, $\cos 60^{\circ}=\frac{base}{80}$

We know, $\cos 60^{\circ}=\frac{1}{2}$

thus, Base = 40 m

AD = 40 m

Thus, the distance between the walls that is the length of ED = 30 + 40 = 70 m

4 0

3 years ago

A train covers a distance of 80 miles in 2 hours. At this rate, about how many hours will it take to cover a distance of 200 mil

Vadim26 [7]

Let's write miles over hours
80 / 2 = 200/ x
cross multiply
80x = 400
divide both sides by 80
x = 5

It will take 5 hours to cover 200 miles

Hope this helps :)

6 0

3 years ago

Q5. Find the simple interest on $950 at 6% per annum for three years.

sveticcg [70]

Answer:

$171

Step-by-step explanation:

=PRN

950×0.06×3

hope this helps and makes sense :))

3 0

3 years ago

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