1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Aleonysh [2.5K]
4 years ago
15

the sum of the ages of Andy and Derek is 50. in 5 years time, the age of Derek will be four times that of Andy now. how old is e

ach boy
Mathematics
1 answer:
AlekseyPX4 years ago
5 0
Andy is 7 and Derek is 43
You might be interested in
X-3y^3+3x^3-5x-x^3-x-2x^3
xxTIMURxx [149]

Answer:

-5x-3y^3

Step-by-step explanation:

x-3y^3+3x^3-5x-x^3-x-2x^3

7 0
3 years ago
Read 2 more answers
Ryan needs to drive 25 miles to work. So far, he has driven 4.2 miles. How many more miles must he drive?
maksim [4K]

{\underline{\orange{\textsf{\textbf{ Answer : }}}}}

➡ He must drive 20.8 miles now.

4 0
3 years ago
Read 2 more answers
Families USA, a monthly magazine that discusses issues related to health and health costs, surveyed 20 of its subscribers. It fo
Harman [31]

Answer:

(a) The 90 percent confidence interval for the population mean yearly premium is ($10,974.53, $10983.47).

(b) The sample size required is 107.

Step-by-step explanation:

(a)

The (1 - <em>α</em>)% confidence interval for population mean is:

CI=\bar x\pm t_{\alpha/2, (n-1)}\times \frac{s}{\sqrt{n}}

Given:

\bar x=\$10,979\\s=\$1000\\n=20

Compute the critical value of <em>t</em> for 90% confidence level as follows:

t_{\alpha/2, (n-1)}=t_{0.10/2, (20-1)}=t_{0.05, 19}=1.729

*Use a <em>t-</em>table.

Compute the 90% confidence interval for population mean as follows:

CI=\bar x\pm t_{\alpha/2, (n-1)}\times \frac{s}{\sqrt{n}}

     =10979\pm 1.729\times \frac{1000}{\sqrt{20}}\\=10979\pm4.47\\ =(10974.53, 10983.47)

Thus, the 90 percent confidence interval for the population mean yearly premium is ($10,974.53, $10983.47).

(b)

The margin of error is provided as:

MOE = $250

The confidence level is, 99%.

The critical value of <em>z</em> for 99% confidence level is:

z_{\alpha/2}=z_{0.01/2}=z_{0.005}=2.58

Compute the sample size as follows:

MOE= z_{\alpha/2}\times \frac{s}{\sqrt{n}}

      n=[\frac{z_{\alpha/2}\times s}{MOE} ]^{2}

         =[\frac{2.58\times 1000}{250}]^{2}

         =106.5024\\\approx107

Thus, the sample size required is 107.

4 0
3 years ago
A nation has five types of coins: sinds, dalts, lorgs, harps, and plunks.
USPshnik [31]
<h3>Answer:  d) plunk</h3>

=================================================

Work Shown:

When comparing units like inches, feet and yards, we need to get everything in the same unit to make a valid comparison. So we'd need to convert everything to inches for instance. The same idea applies to these five coins. We need to get everything in either lorgs, sinds, plunks, harps or dalts (pick one of those five).

It's effectively the same as trying to convert dollars into cents (eg: $1.37 converts to 137 cents). Or you can think of it as 1 dollar = 100 cents, 1 quarter = 25 cents, 1 dime = 10 cents, and so on.

The steps in the various sections below will aim to get all the coins converted to lorgs as our base unit. I found the lorg coin to be the smallest of value through trial and error, which is why I'm aiming to get everything in terms of lorgs.

The four given equations are

  • 1 sind = 4 lorgs
  • 2 plunks = 5 dalts
  • 5 sinds = 2 harps
  • 1 plunk = 3 harps

I'll refer to them as equation (1) through equation (4) in that order above.

--------------

1 sind = 4 logs .... equation (1)

5 sinds = 20 lorgs .... multiply both sides by 5

2 harps = 20 lorgs .... replace "5 sinds" with "2 harps" from equation (3)

1 harp = 10 lorgs .... divide both sides by 2; call this equation (5)

--------------

1 plunk = 3 harps .... equation (4)

1 plunk = 3*(1 harp)

1 plunk = 3*(10 lorgs) .... plug in equation (5)

1 plunk = 30 lorgs .... call this equation (6)

---------------

2 plunks = 5 dalts ..... equation (2)

5 dalts = 2 plunks

5 dalts = 2*(1 plunk)

5 dalts = 2*(30 lorgs) .... replace 1 plunk with 30 lorgs; see equation (6)

5 dalts = 60 lorgs

1 dalt = 12 lorgs ..... divide both sides by 5; call this equation (7)

----------------

We found the following conversions:

  • 1 sind = 4 lorgs .... given as equation (1)
  • 1 dalt = 12 lorgs .... found earlier as equation (7)
  • 1 harp = 10 lorgs .... equation (5)
  • 1 plunk = 30 lorgs  .... equation (6)

Each of those equations helps us see how much the value of the coins sind, dalt, harp, plunk are in terms of lorgs.

We can see that 1 plunk yields the most lorgs at 30. So the plunk coin is the most valuable. The lorg coin is least value since you need 4 of those coins to make the second lowest coin of 1 sind.

The order of the coins value from least to greatest is: lorg, sind, harp, dalt, plunk.

5 0
3 years ago
Solve |5 - 8x| - 7 &lt; 8<br><br>​
sammy [17]
Move all terms not containing
|
5
−
8
x
|
|
5
-
8
x
|
to the right side of the inequality.
Tap for fewer steps...
Add
7
7
to both sides of the inequality.
|
5
−
8
x
|
<
8
+
7
|
5
-
8
x
|
<
8
+
7
Add
8
8
and
7
7
.
|
5
−
8
x
|
<
15
|
5
-
8
x
|
<
15
Remove the absolute value term. This creates a
±
±
on the right side of the inequality because
|
x
|
=
±
x
|
x
|
=
±
x
.
5
−
8
x
<
±
15
5
-
8
x
<
±
15
Set up the positive portion of the
±
±
solution.
5
−
8
x
<
15
5
-
8
x
<
15
Solve the first inequality for
x
x
.
Tap for more steps...
x
>
−
5
4
x
>
-
5
4
Set up the negative portion of the
±
±
solution. When solving the negative portion of an inequality, flip the direction of the inequality sign.
5
−
8
x
>
−
15
5
-
8
x
>
-
15
Solve the second inequality for
x
x
.
Tap for more steps...
x
<
5
2
x
<
5
2
Set up the intersection.
x
>
−
5
4
x
>
-
5
4
and
x
<
5
2
x
<
5
2
Find the intersection between the sets.
−
5
4
<
x
<
5
2
-
5
4
<
x
<
5
2
The result can be shown in multiple forms.
Inequality Form:
−
5
4
<
x
<
5
2
-
5
4
<
x
<
5
2
Interval Notation:
(
−
5
4
,
5
2
)
(
-
5
4
,
5
2
)

6 0
3 years ago
Read 2 more answers
Other questions:
  • 7. Order the numbers from greatest to<br> least.<br> (12.012 12.001 12.102 12.01
    6·1 answer
  • 8 times 10 to the power of 5 is how many as great as 8 times 10 to the power of -1
    15·2 answers
  • An accountant forgets to record a transaction. What type of error is this?
    6·2 answers
  • Evaluate f(x) = x2 + 1 for f(-1)
    12·2 answers
  • HELP ME QUICK!!!!!!!!!!!!!!!!!!!!!!!
    12·1 answer
  • Please help someone!!
    14·2 answers
  • 15y^2-15y+2y+7-2y^2+4
    8·1 answer
  • Please help with this question
    11·1 answer
  • In a city with three high schools, all the ninth graders took a Standardized Test, with these results:High Scool Mean Score test
    9·1 answer
  • Please answer all these questions right I can’t do them ‍♀️
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!