A single card is drawn from a standard 52 card deck.

Use the "rule of 72" to estimate the doubling time (in years) for the interest rate, and then calculate it exactly. (Round your

bonufazy [111]

Answer:

Using the rule of 72, the doubling time is 9.35 years.

The exact answer is that the doubling time is 8.89 years.

Step-by-step explanation:

By the rule of 72, we have that the doubling time D is given by:

$D = \frac{72}{Interest Rate}$

The interest rate is in %.

In our exercise, the interest rate is 7.7%. So, by the rule of 72:

$D = \frac{72}{7.7} = 9.35$ .

Exact answer:

The exact answer is going to be found using the compound interest formula(since the rule of 72 is a simplification of this formula).

The compound interest formula is given by:

$A = P(1 + \frac{r}{n})^{nt}$

Where A is the amount of money, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per unit t and t is the time the money is invested or borrowed for.

So, for this exercise, we have:

We want to find the doubling time, that is, the time in which the amount is double the initial amount, double the principal.

$A = 2P$

$r = 0.077$

There are 52 weeks in a year, so $n = 52$

$A = P(1 + \frac{r}{n})^{nt}$

$2P = P(1 + \frac{0.077}{52})^{52t}$

$2 = (1.0015)^{52t}$

Now, we apply the following log propriety:

$\log_{a} a^{n} = n$

So:

$\log_{1.0015}(1.0015)^{52t} = \log_{1.0015} 2$

$52t = 462.44$

$t = \frac{462.44}{52}$

$t = 8.89$

The exact answer is that the doubling time is 8.89 years.

6 0

3 years ago

The circumference of a circular garden is 84 feet. What is the diameter of the garden

swat32

Diameter is 25.46 feet as circumference is 2πr and 2r is d so we just simply divide the circumference with π and get the value as 25.46

Step-by-step explanation:

6 0

1 year ago

Read 2 more answers

In a lab experiment, 3400 bacteria are placed in a petri dish. The conditions are such that the number of bacteria is able to do

nalin [4]

Answer: 16.1

Step-by-step explanation:

3 0

3 years ago

2.the solution set of x +y =5 and x-y =3

Nataliya [291]

Answer:

Check the solution below

Step-by-step explanation:

2) Given the equation

x +y =5... 1 and

x-y =3 ... 2

Add both equations

x+x = 5+3

2x = 8

x = 8/2

x = 4

Substitute x = 4 into 1:

From 1: x+y = 5

4+y= 5

y = 5-4

y = 1

3) Given

x+3y =15 ... 1

2x+7y=19 .... 2

From 2: x = 15-3y

Substitute into 2

2(15-3y)+7y = 19

30-6y+7y = 19

30+y = 19

y = 19-30

y = -11

Substitute y=-11 into x = 15-3y

x =15-3(-11)

x = 15+33

x = 48

The solution set is (48, -11)

4) given

x/2 +y/3 =0 and x+2y=1

From 1

(3x+2y)/6 = 0

3x+2y = 0.. 3

x+2y= 1... 4

From 4: x = 1-2y

Substutute

3(1-2y) +2y = 0

3-6y+2y = 0

3 -4y = 0

4y = 3

y = 3/4

Since x = 1-2y

x = 1-2(3/4)

x = 1-3/2

x= -1/2

The solution set is (-1/2, 3/4)

5) Given

5.x=1/2 and y =x +1 then solution is

We already know the vkue of x

Get y

y= x+1

y = 1/2 + 1

y = 3/2

Hence the solution set is (1/2, 3/2)

6) Given

3x +y =5 and x -3y =5

From 3; x = 5+3y

Substitute into 1;

3(5+3y)+y = 5

15+9y+y = 5

10y = 5-15

10y =-10

y = -1

Get x;

x = 5+3y

x = 5+3(-1)

x = 5-3

x = 2

Hence two solution set is (2,-1)

6 0

3 years ago

Please help! <br><br> If f (x) = 1/9 x-2 what is f^-1(x)

saw5 [17]

Answer:

Its C or the 3rd option

(9x+2)

Step-by-step explanation:

You have to inverse the equation meaning do everything the opposite so for example, add the 2 to the other side of the equation

4 0

3 years ago