A man has two sons, one twice as old as the other. The man is four times as old as the older boy. In three years he will be five times as old as the younger boy. Find their present ages.

Answers

Answer 1

Answer:

Man's present age: 32 years

Older son's present age: 8 years

Younger sons present age: 4 years

Step-by-step explanation:

Let their present ages be represented by:

Man = a

Older boy = b

Younger boy = c

A man has two sons, one twice as old as the other:

b = 2 × c

b = 2c......... Equation 1

The man is four times as old as the older boy:

a = 4 × b

a = 4b.......Equation 2

In three years he will be five times as old as the younger boy:

a + 3 = 5 (c + 3)

a + 3 = 5c + 15........Equation 3

Since b = 2c and a = 4b

Subtitute 2c for b in Equation 2

a = 4b

a = 4 × 2c

a = 8c

Subtitute 8c for a in Equation 3

a + 3 = 5c........Equation 3

8c + 3 = 5c + 15

Collect like terms

8c - 5c = 15 - 3

3c = 12

c = 4

Therefore since c, represents the present age of the younger son, the younger son is 4 years old

b = 2c

b = 2 × 4

b = 8

Since b is the present age of the older son, the older son is 8 years old

a = 4b

b = 8

a = 4 × 8

a = 32

Since a is the present age of the man, the man is 32 years old

Therefore,

Man's present age: 32 years

Older son's present age: 8 years

Younger sons present age: 4 years


Related Questions

What percentage is 420 grams of 750 grams?
%

Answers

Mark Brainliest please

Answer: 56%

Explanation:

Divide the numerator by the denominator to get fraction's value:

420/750 =

420 ÷ 750 =

0.56

What are the irrational numbers between minus 12 and plus 49

Answers

Answer:

First, an irrational number is a number that has infinite digits after the decimal point, in such way that those digits do not form any pattern.

The irrational set is called a dense set, wich means that in between two elements of the set, we can find infinite other elements of the set.

For example, between 1 and 2, we have

1.12312412513513532....

1.123224124312432432....

and between those two numbers, we can find infinite irrational numbers, and so on.

Then between -12 and +49, we have infinite irrational numbers.

In the figure shown, what is the measure of angle x? (5 points) 115 degrees 130 degrees 145 degrees 150 degrees

Answers

Answer:

x=115

Step-by-step explanation:

180 - (115) =65(triangle)

65 + x = 180(on a line)

x=180-65

x = 115

Answer:

115 degrees

Step-by-step explanation:

the person above me is right, but there is an easier way.

Just add 50 and 65 degrees and boom you have your answer.

Question choices:
A: I, IV

B: II, III, IV

C: III, IV

D: II, III

Answers

0Answer:

A

Step-by-step explanation:

Find the zeros by letting y = 0 , that is

x² - x - 6 = 0 ← in standard form

(x - 3)(x + 2) = 0 ← in factored form

Equate each factor to zero and solve for x

x - 3 = 0 ⇒ x = 3

x + 2 = 0 ⇒ x = - 2

Since the coefficient of the x² term (a) > 0

Then the graph opens upwards and will be positive to the left of x = - 2 and to the right of x = 3 , that is in the intervals

(-∞, - 2) and (3, ∞ ) → option A

Teresa earns $8.23 per hour. Calculate her wage for a week where she
works 14h 30min.

Answers

Answer:

$119.335

Step-by-step explanation:

8.23 per hour

14h 30 mins = 14.5 hrs

8.23*14.5 = 119.335

Answer:

238.67

Step-by-step explanation:

John earns $6 per hour for mowing the lawn. If t represents John's total earnings for h hours of mowing, which equations can be used to model the situation

Answers

Answer:

h=6

Step-by-step explanation:

write as an inequality 9 is greater than or equal to w, and -7 is less than or equal to w

Answers

[tex]9 \geqslant w \\ \\ - 7 \leqslant w[/tex]

"9 is greater than or equal to w" translates to [tex]9 \ge w[/tex] which flips to [tex]w \le 9[/tex]. We swap both sides and flip the inequality sign as well.

"-7 is less than or equal to w" translates to [tex]-7 \le w[/tex]

We have [tex]-7 \le w[/tex] and [tex]w \le 9[/tex] which then ultimately combine into the compound inequality [tex]-7 \le w \le 9[/tex]

Final Answer: [tex]-7 \le w \le 9[/tex]

Rebecca is saving money to purchase a laptop, which costs $1,099.51. She has already saved $354.20 and plans to continue
saving $50.60 per week. Which inequality could be used to find w, the number of weeks that Rebecca must save in order to
purchase the laptop?
OA $354.20 + $50.60w < $1,099.51
OB. $354.20w+ $50.60 $1,099.51
OC $354.20 + $50.60w< $1,099.51
OD. $354.20 + $50.60w $1,099.51

Answers

Answer:

354.20 + 50.60w ≥ 1099.51

Step-by-step explanation:

354.20 + 50.60w ≥ 1099.51

Find the surface area of the composite figure

Answers

Answer:

384 cm^2

Step-by-step explanation:

Start with the prism (I multiply by 2 because some of the surfaces are more of):

4×15×2=1206×15×2=1806×4=24

The Triangular Prism (I divide by 2 because it is a triangle shape on the sides):

3×4/2*2=123×6=186×5=30

The Last Step (adding everything):

120+180+24+12+18+30=384

PLEASE FIND THE ANSWER FOR B.)

Answers

Answer:

f (-3)

since -3 is between-4 and -2 for every value of x y is 2

What is x/y ? Help pls

Answers

Answer:

ok I really suck at math, but I think you may have to multiply the x/y to get the whole area of the circle. so maybe itd be 10x25. I'm sorry if this isnt correct

Is the relation a function?

Answers

Answer:

Yes it's a function

Step-by-step explanation:

ANSWER:
Yes it is a function.

The sum of Rhonda and her daughter Tenica’s age is 64. The difference in their ages is 28. How old is each person?

Answers

Answer:

The mother (Rhoda) is 46 years old.

The daughter (Tenica) is 18 years old

Step-by-step explanation:

Let the age of the mother (Rhoda) be m

Let the age of the daughter (Tenica) be d.

The sum of Rhonda and her daughter Tenica’s age is 64. This can be written as:

m + d = 64 ... (1)

The difference in their ages is 28. This can be written as:

m – d = 28 ... (2)

From the above illustrations, the equation obtained are:

m + d = 64 ... (1)

m – d = 28 ... (2)

Solving by elimination method:

Add equation 1 and 2 together

. m + d = 64

+ m – d = 28

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

2m = 92

Divide both side by 2

m = 92/2

m = 46

Substitute the value of m into any of the equation to obtain the value of d. Here, we shall use equation 1

m + d = 64

m = 46

46 + d = 64

Collect like terms

d = 64 – 46

d = 18

Therefore, the mother (Rhoda) is 46 years old and the daughter (Tenica) is 18 years old.

Which expression is equivalent to -3+(-9)?
O 3+ (-9)
0 –9 – (-3)
Submit Answer
0-3 – (-9)
0-3 - 9

Answers

Answer:

-3-9

Step-by-step explanation:

+(-) = -

-3-9 is the answer:)) if you see +(-) together it would bcome minus. Hope you understand it<33

ABC is an eqilateral triangle with sides 10cm find the length of the prependicular from A to BC

Answers

All sides are equal in an equilateral triangle and the perpendicular bisects the side too.

so BC will be bisected and the segments be 5 each.

you can use Pythagoras theorem to find the altitude length, hypotenuse will be one side of the triangle.

[tex] 5^2+h^2=10^2[/tex]

$h^2=100-25=75$

$h=\sqrt{75}=5\sqrt3$

For every 5 books her students read, Mrs. Fenway gives them 4 homework passes. Juan has earned 12 homework passes. What proportion shows how many books Juan has read?

4/12 = x/5
4/5 = x/12
4/5 = 12/x
5/12 = 4/x

Answers

Okay which class.are you first thing is that .. ok tell me then fast.

Need help will give good rating.

Answers

Answer:

the third one is correct

Answer:

Step-by-step explanation:

dlklf,vkvkdcñclcdliffo

What is the solution to the equation? Show your work and explain your answer. 4(x+2)−1=4x+7

Answers

Answer:

infinitely many solutions / all real numbers

Step-by-step explanation:

distribute the 4 on the left side of the equation

4 • x = 4x

4 • 2 = 8

4x + 8 - 1 = 4x + 7

combine like terms

4x + 7 = 4x + 7

0 = 0

since this expression is true, there are infinitely many solutions

4x+8-1=4x+7
x=x


There are infinitely many solutions. Any number works.

Simplify.
-4a(3a - 6)

Answers

First change the -6 to plus a negative 6.

Then distribute the -4a through the parentheses.

So we have -4a(3a) + -4a(-6).

Remember that -4a(3a) is -12a² and -4a(-6) is 24a.

So the answer is -12a² + 24a.

Answer:

-12a^2 +24a

Step-by-step explanation:

-4a(3a - 6)

Distribute

-4a*3a -4a * -6

-12a^2 +24a

Find the mean of the data in the bar chart below. coins collected by each person in a scavenger hunt.

Answers

Answer:

There's no chart below

Step-by-step explanation:

Answer:

6.2 coins he will have

Step-by-step explanation:

its the anwser on han i go it wrong :( the first time and 12 was the anwser!

x + 12 = 6 what is the answer

Answers

Answer:

-6

Step-by-step explanation:

x + 12 = 6

 - 12      - 12

so

12-12=0

6-12=-6

put into equation

x + 0 = -6

x = -6

Please help! Find the surface area of the composite figure

Answers

Answer:

Step-by-step explanation:

area of base=6×6=36 m²

surface area of four walls=4×6×12=144 m²

area of top= area of four triangles=4×1/2×6×5=60 m²

total surface area=36+144+60=240 m²

help please i need the answer to this

Answers

Answer:

140 degrees

Step-by-step explanation:

first start by making the given angles equal each other because they are congruent.

2x+28=6x+4

Subtract 4 on both sides

2x+24=6x

subtract 2x on both sides

24=4x

divide both sides by 4 to get x

24/4=4x/4

6=x

next to find the actual number of the angle, plug 6 back into either one of the equations. Im gonna use the first one.

2x + 28

2(6) + 28

12+28= 40

Now that we have the number, we already know that a full circle is 360 degrees so half a circle is 180.

Take 40 and subtract from 180

180-40= 140

Well, m∠1 and m∠3 are congruent by the Vertical Angle Congruent Theorem (VACT). This means that because the angles are opposite of each other, their angles are the same because they are formed by the same two intersecting lines.

Because of this, we can set m∠1 and m∠3 equal to each other:

m∠1 = m∠3

(2x + 28) = (6x + 4)

2x + 28 = 6x + 4

-4x + 28 = 4

-4x = -24

-x = -6

x = 6

Knowing that x equals 6, we can use this to find m∠2. By the Supplementary Angles Theorem (SAT), angles that are on the same line add up to equal 180°. To use the SAT, we need to plug x in to find m∠1 or m∠3, because they are both the same:

x = 6

m∠1 = (2x + 28)

m∠1 = 2(6) + 28

m∠1 = 12 + 28

m∠1 = 40°

m∠3 also equals 40°.

Now that we have the value for ∠1 (or ∠3), we can use the SAT:

m∠2 + m∠3 = 180 ← You could also use m∠1, because they both equal the same!

m∠2 + 40 = 180

m∠2 = 140°

So, the measure of ∠2 is 140°.

If you have any questions, feel free to ask! :)

what is square root of the product of the number z and itself

Answers

Answer:

[tex]\large\boxed{z}[/tex]

Step-by-step explanation:

What is square root of the product of the number z and itself?

Break down into smaller parts

What is the product of the number z and itself?

Product = multiply

Write an equation multiplying z by itself

z * z

Bring back the full question: What is the square root of the product of the number z and itself?

Now we can just add a [tex]\sqrt{}[/tex] to the front of our equation to solve the problem.

[tex]\sqrt{z * z}[/tex]

Simplify

z * z = [tex]z^{2}[/tex]

[tex]\sqrt{z^{2} }[/tex]

In this case, the square root cancels out the exponent ([tex]z^{2}[/tex]), so [tex]\sqrt{z^{2} }[/tex] can simplify to z.

Hope this helps :)

in a 41-49 right triangle, the hypotenuse is 28.83 centimeters. if cos 41= 0.7547, find the length of the side opposite the 49 angle. Estimate your answer to three decimal places

Answers

Answer:

21.758

Step-by-step explanation:

If you draw the triangle out, you find that cos 41 = x/28.83, when x is equal to the side opposite the 49 angle

Simplify this into 28.83 cos 41, and plug it into the calculator and you get

21.75827.

What percent of 500 is 125

Answers

Answer:

25%

Step-by-step explanation:

125 of 500 can be written as:  125 /500

To find a percentage, we need to find an equivalent fraction with the denominator 100. Multiply both numerator & denominator by 100.  

125 /500  ×  100 /100

= ( 125 × 100/ 500 ) ×  1 /100   =  25 /100

Answer:

25%

Step-by-step explanation:

Of means multiply and is means equals

P *500 = 125

Divide each side by 500

P = 125/500

P = .25

Change to percent form

P = 25%

PLEASE HELP ME!!! I will mark brainliest!!!

The image above shows two dilated figures with lines IJ and JK drawn. If the smaller figure was dilated by a scale factor of 2, what relationship do lines IJ and KL have?

Answers

Answer:

parallel lines

Step-by-step explanation:

Lines IJ and KL are parallel. Since in a dilation there is no rotation, a line becomes either the same line or a parallel line.

How many times more ?

Answers

Answer:

1.3

Step-by-step explanation:

bc for each time x increases by 1, it multiplies by 1.3

i cant think of any other way to explain it

but   i hope this helped :D

Answer:

1.3 times

Step-by-step explanation:

f(x)= 68 (1.3) ^x

it, means each year, the expected number of squirrels is 1.3 times, the number the year before.

x=0 so, f(0)=68

New x=1, so f(1)= 68(1.3)¹

= 68 × 1.3

f (1)= f(0) × 1.3

So, 1.3 times

OAmalOHopeO

A shopkeeper sells a DVD player at a price RM 2,500. If the cost price of the DVD player was RM 3,500, find the profit/loss in which the shopkeeper is. Also, find the percent for the same. ​

Answers

Answer:

see explanation

Step-by-step explanation:

Since the player was sold for less than what was paid then a loss is made.

loss = 3500 - 2500 = 1000

percent loss = [tex]\frac{loss}{cost}[/tex] × 100% , thus

percent loss = [tex]\frac{1000}{3500}[/tex] × 100% ≈ 28.6% ( to 1 dec. place )

Find the volume of the given shapes. Round to the nearest tenth if necessary.

Answers

Answer:

Step-by-step explanation:

5.

volume=l×w×h=8×6×7=336 mi³

6.

diameter=16 yd

radius=16/2=8 yd

[tex]volume=\frac{4}{3} \pi \times 8^3=\frac{2048}{3} \pi \approx 2144.67 \approx 2144.7 yd^3[/tex]

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