Solve y - 3x + 15 = 10

The population of the world was 7.1 billion in 2013, and the observed relative growth rate was 1.1% per year. A) Estimate how lo

VLD [36.1K]

Answer:

A) 63.36 years.

B) 100.42 years.

Step-by-step explanation:

We have been given that the population of the world was 7.1 billion in 2013, and the observed relative growth rate was 1.1% per year.

A) Since we know that population increases exponentially, therefore we will use our given information to form an exponential model for population increase and then we will solve for the time by which our population will be double.

$P(t)=7.1(1.011)^{t}$

$7.1 \times 2=7.1(1.011)^{t}$

$\frac{7.1 \times 2}{7.1} =(1.011)^{t}$

$2 =(1.011)^{t}$

Now let us solve for t using logarithm.

$ln(2) =ln (1.011)^{t}$

$ln(2) =t \cdot ln(1.011)$

$0.6931471805599453 =t \cdot 0.0109399400383344$

$t=\frac{0.6931471805599453}{0.0109399400383344}$

$t=63.3593217267282743049\approx 63.36$

Therefore, it will take 63.36 years the population to be double.

B) Now we will find the number of years it will take the population to be triple of its size.

$7.1 \times 3=7.1(1.011)^{t}$

$\frac{7.1 \times 3}{7.1} =(1.011)^{t}$

$3 =(1.011)^{t}$

Now let us solve for t using logarithm.

$ln(3) =ln (1.011)^{t}$

$ln(3) =t \cdot ln(1.011)$

$1.0986122886681097 =t \cdot 0.0109399400383344$

$t=\frac{1.0986122886681097}{0.0109399400383344}$

$t=100.4221490079915311298\approx 100.42$

Therefore, it will take 100.42 years the population to triple of its size.

6 0

2 years ago

A complex electronic system is built with a certain number of backup components in its subsystems. One subsystem has four identi

Tcecarenko [31]

Answer:

a. 0.1536

b. 0.9728

Step-by-step explanation:

The probability that a component fails, P(Y) = 0.2

The number of components in the system = 4

The number of components required for the subsystem to operate = 2

a. By binomial theorem, we have;

The probability that exactly 2 last longer than 1,000 hours, P(Y = 2) is given as follows;

P(Y = 2) = $\dbinom{4}{2}$ × 0.2² × 0.8² = 0.1536

The probability that exactly 2 last longer than 1,000 hours, P(Y = 2) = 0.1536

b. The probability that the system last longer than 1,000 hours, P(O) = The probability that no component fails + The probability that only one component fails + The probability that two component fails leaving two working

Therefore, we have;

P(O) = P(Y = 0) + P(Y = 1) + P(Y = 2)

P(Y = 0) = $\dbinom{4}{0}$ × 0.2⁰ × 0.8⁴ = 0.4096

P(Y = 1) = $\dbinom{4}{1}$ × 0.2¹ × 0.8³ = 0.4096

P(Y = 2) = $\dbinom{4}{2}$ × 0.2² × 0.8² = 0.1536

∴ P(O) = 0.4096 + 0.4096 + 0.1536 = 0.9728

The probability that the subsystem operates longer than 1,000 hours = 0.9728

4 0

2 years ago

Solving an Equation for a Given Variable

Reil [10]

Answer:

$a=\frac {f-v}{t}$

Step-by-step explanation:

f=v+at

It requires you to make a the subject of the formula

f-v=at

Dividing both sides by t then

$a=\frac {f-v}{t}$

Therefore, the equivalent for a is $a=\frac {f-v}{t}$

8 0

2 years ago

Grapes cost $3.25 per pound. Darius paid a total of $26 for grapes.

Dmitry [639]

Answer:He buys 8 pounds

Step-by-step explanation:

You can either just add up the $3.25 until you get to the end-price, but that wont always work for every problem. The best way is to divide the 26 with the 3.25 in a written devision.

4 0

3 years ago

Read 2 more answers

What is the solution to the system of linear equations graphed below?

dalvyx [7]

Answer:

the answer is A.) or (3 and one-half, negative 4)

7 0

3 years ago

Read 2 more answers