What is 999 - 1 -1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 +1 + 11 -1 = ???

Tina is saving to buy a notebook computer. She has two options. The first option is to put $500 away initially and save $10 ever

Alexxandr [17]

Answer:

Tina would save the same amount using either option after 20 months.

With either option, Tina would save $700.

Step-by-step explanation:

This problem can be modeled by a first order equation:

Where Tina's saved money after n months is:

S(n) = S(0) + rn, where S(0) is the money put away initially and r is how much she saves every month.

The first option is to put $500 away initially and save $10 every month, so:

$S_{1}(n) = 500 + 10n$

The second option is to put $100 away initially and save $30 every month, so:

$S_{2}(n) = 100 + 30n$

After how many months would Tina save the same amount using either option?

It will happen at the month n in which $S_{1}(n) = S_{2}(n)$ , so:

$S_{1}(n) = S_{2}(n)$

500 + 10n = 100 + 30n

500 - 100 = 30 - 10n

400 = 20n

20n = 400

$n = \frac{400}{20}$

n = 20.

Tina would save the same amount using either option after 20 months.

How much would she save with either option?

We can choose $S_{1}(20)$ or $S_{2}(20)$ , since they are equal

$S_{1}(20) = 500 + 10(20) = 500 + 200 = 700$

With either option, Tina would save $700.

3 0

3 years ago

Y varies directly as x. Y=42 when x=6. Find the value of y when x =15.

pentagon [3]

Answer:

y=120

Step-by-step explanation:

Y varies directly as x is written as

$y \alpha x$

introducing a constant

y=kx

from the question, when y=48, x=6

substitute it in the formula

48=6k

making k the subject by dividing through by 6

$\frac{48}{6} = \frac{6k}{6}$

k=48/6

k=8

put the value of k in the expression y=kx

y=8x

from the question,the value of y when x=15 is given by

y=8×15

y=120.

4 0

3 years ago

HELP ME!!! I WILL MARK AS BRAINLY

borishaifa [10]

Answer:

4

Step-by-step explanation:

We can see from the two marked points the coordinates are: (2, 8) and (4, 16)

That means the rise (vertical change) is 16 - 8 = 8 units. And the run (horizontal change) is (4 - 2) = 2 units.

Therefore slope = rise/run = 8/2 = 4.

4 0

3 years ago

A May 2000 Gallup poll found that 38% of the people in a random sample of 1,012 adult Americans said that they

Alex777 [14]

Answer:

10.

x P(X)

0 0.238

1 0.438

2 0.269

3 0.055

11.

0.707

There is 70.7% chance that at least one but at most two adults in the sample believes in the ghost

12.

1.14≅1

There will be one adult out of three we expect to believe in the ghost

Step-by-step explanation:

The probability distribution is constructed using binomial distribution.

We have to construct the probability distribution of the number adults believe in ghosts out of three adults. so,

x=0,1,2,3

n=3

p=probability of adults believe in ghosts=0.38

The binomial distribution formula

nCxp^xq^n-x=3cx0.38^x0.62^3-x

is computed for x=0,1,2,3 and the results depicts the probability distribution of the number adults believe in ghosts out of three adults.

x P(X)

0 0.238

1 0.438

2 0.269

3 0.055

11.

P(at least one but at most two adults in the sample believes in the ghost )= P(x=1)+P(x=2)=0.437+0.269=0.707

P(at least one but at most two adults in the sample believes in the ghost )=70.7%

12. E(x)=n*p

here n=3 adults and p=0.38

E(x)=3*0.38=1.14

so we expect one adult out of three will believe in the ghosts.

4 0

3 years ago

A candy store held a contest to guess the total number of jelly beans in a jar. All of the jelly beans in the jar were either gr

Fudgin [204]

Answer:

Step-by-step explanation:

Let the number of orange jelly beans be x , as we do not know the exact value of it yet. There are 12 times as many green jelly beans than the orange ones. So , if the number of orange jelly beans is x , the number of green jelly beans will be = 12 times x , which can be written as 12x. Now there are a total of 1872 jelly beans , but they are either orange or green , so we already know that the number of orange jbs is x , and the number of green jelly beans is 12x. So if we the green jelly beans and orange jelly beans , it should be 1872.

Now all we need to do is to find x.

We know that ,

x + 12x = 1872

Now we add x and 12x on the left hand side

13x = 1872

Now we divide both sides by 13 to get x. (That includes 1872 as well)

x = 144

Now we have the value of x which is 144

We know that the number of green jelly beans was 12 times x

So the number of green jelly beans in numeric value is : 12 * 144

As x is equal to 144

Ans . : The number of green jelly beans is 1728.

6 0

3 years ago