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
sattari [20]
3 years ago
9

3 years ago a father was 3 times as old as his son, in five years time he will be twice as old as his son, what will be the sum

of their years in four years time​
Mathematics
2 answers:
ivolga24 [154]3 years ago
5 0

Answer: 46 years

Step-by-step explanation:

Let the father's age be x and the son's age be y, then 3 years ago:

Father = x - 3

son     = y - 3

Then , from the first statement :

x - 3 = 3 ( y - 3 )

x - 3 = 3y - 9

x     = 3y - 9 + 3

x     = 3y - 6 .......................................... equation 1

In five years time

father = x + 5

son = y + 5

Then , from the second statement

x + 5 = 2 ( y + 5 )

x + 5 = 2y + 10

x       = 2y + 10 - 5

x       = 2y + 5 ........................ equation 2

Equating equation 1 and 2 , we have

3y -6 = 2y + 5

add 6 to both sides

3y = 2y + 5 + 6

subtract 2y from both sides

3y - 2y = 11

y = 11

substitute y = 11 into equation 1 to find the value of x

x = 3y - 6

x = 3(11) - 6

x = 33 - 6

x = 27

This means that the father is presently 27 years and the son is presently 11 years.

In four years time

father = 27 + 4 = 31

son = 11 + 4      = 15

sum of their ages in four years time will be

31 + 15 = 46 years

docker41 [41]3 years ago
4 0

Answer:

46 years

Step-by-step explanation:

Answer:

Step-by-step explanation:

In solving this, we'll make some keen assumptions to solve the question.

We'll represent the father's age with "a"

And represent the sons age as "b"

Lets interpret the question.

3 years ago, (means in the past), we'll subtract.

Therefore:

Father's age = a - 3

Sons age = b - 3

The sentence said, " 3 years ago, father was 3 times the sons age*. Interpreting that becomes:

a - 3 = 3 times (b - 3)

Simplifying that gives :

a - 3 = 3(b - 3)

a - 3 = 3b - 9

a = 3b - 9 + 3

a = 3b - 6 ( FIRST EXPRESSION )

The next line says: In five years time (that's in the future, hence we add) he'll be twice his sons age.

Therefore I become:

Father : a + 5

Son : b + 5

a + 5 = 2(b + 5)

a + 5 = 2b + 10

a = 2b + 5 ( SECOND EXPRESSION)

Equating the first and second equation to solve for "a" - the father's age

3b - 6 = 2b + 5

b = 5 + 6

b = 11 years (Sons age)

Substitute b = 1 in the first expression.

a = 3b - 6

a = 3(11) - 6

a = 33 - 6

a = 27 years (Father's age)

Let resolve, the last sentence:

What will be the sum of their ages in 4 years time. (SINCE IT'S IJ THE FUTURE, WE ADD)

Father's age in four years time: 27 + 4 = 31

Son's age in four years time: 11 + 4 = 15.

The sum of their ages in same four years time becomes:

31 + 15 (years)

46 years

You might be interested in
Write the quadratic function 5x2 - 40x + 60 in its vertex form by completing the square. Then
siniylev [52]
There’s no turning point bc the multiplicity is one

3 0
3 years ago
Read 2 more answers
write three ratios that are equivalent to the one given: The ratio of right-handed students to left-handed students is 18;4.
Ainat [17]
9 : 2 = 18 : 4

As: 9 x 2 : 2 x 2 = 18 : 4

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

36 : 8 = 18 : 4

As: 18 x 2 : 4 x 2 = 36 : 8

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

72 : 16 = 18 : 4

As: 18 x 4 : 4 x 4 = 72 : 16
6 0
3 years ago
In a computer game, a bird flies at a height of 1,281 feet. At the same time, a fish swims 282 feet below sea level. What is the
Nana76 [90]

Answer:

The difference is 1,563 feet.

Step-by-step explanation:

1,281+282=1,563

5 0
3 years ago
Help me pls this is 8th grade math fastest answer gets brainliest show work pls
miskamm [114]

Answer:

1: x ^11

2: y ^12

3: x^ 7

Step-by-step explanation:

In 1 we give the sum

In 2 we give the multiple

In 3 we minus

3 0
3 years ago
Read 2 more answers
Joe runs each lap in 5 minutes. He will run at least 12 laps today. What are the possible numbers of minutes he will run today?
worty [1.4K]

Answer:

at least 60 min (1 hour)

Step-by-step explanation:

we know that a lap takes 5 min.

and we know he will run At least 12 laps

that means that the least number of min.he can run is 5x12=60

So, 60min is the answer

8 0
3 years ago
Read 2 more answers
Other questions:
  • 547321 rounded to nearest one thousand
    10·1 answer
  • A 1,000 gallon pool (no top) with a rectangular base will be constructed such that the length of the base is twice the width. Fi
    7·1 answer
  • In the past two weeks, Sue earned $513 at her part-time job. She worked a total of 54 hours. About how much did she earn per hou
    10·2 answers
  • A project has an initial cost of $40,000, expected net cash inflows of $10,000 per year for 8 years, and a cost of capital of 14
    11·1 answer
  • Allies plant has a height of 6meters. Radon’s plant grows 3/10 meters higher. How high does radon’s plant grow
    12·1 answer
  • What fraction is equal to the decimal 0.4?
    6·2 answers
  • Linda collects a random sample of 12 of the 98 Wildness Club members ages. She makes an inference that most wilderness club memb
    12·1 answer
  • Which expressions are equal to 105?
    13·1 answer
  • Help smart teachers or people help
    9·1 answer
  • Please solve this problem. I can't solve it! And can someone explain how to do it please??
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!