answersLogoWhite

0


Best Answer

4 years ago Jane was 8, Sam was 4. In 4 years from now, Jane will be 16 and Sam will be 12.

So Jane is 12 years old now.

Let's turn this into an algebra problem

We'll use J for Jane's age now, and S for Sam's age now, and make an equation which shows the relationship four years ago.

J - 4 = 2(S - 4) and we'll work out the brackets and move the unknowns to the same side

J - 4 = 2S - 8

J - 2S = - 8 + 4

J - 2S = - 4

Now we'll do another equation to show the relationship in four years time

3/4(J + 4) = S + 4 --- and we'll multiply both sides by 4 to get rid of that fraction

3(J + 4) = 4(S + 4)

3J + 12 = 4S + 16

3J - 4S = 16 - 12

3J - 4S = 4

Now we need to make one of the unknown the same value so we can subtract the two equations.... if we multiply the top one by -3 we get

-3J +6S = 12, and if we add that to the second equation we will get a new equation with no J value

3J - 4S = 4

-3J +6S = 12

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

0J + 2S = 16

Therefore S = 8, and we can now substitute 8 for S in any of the other equations, and check the answer we get for J

J - 2(8) = - 4

J - 16 = - 4

J = - 4 + 16

J = 12

Now, if we are right then substituting these values not the second equation should give a correct sum.

3J - 4S = 4

3(12) - 4(8) = 4

36 - 32 = 4

Which is correct,.... so we know that the calculations are right.

To put that whole puzzle into real number then we look at he first statement

Four years ago Jane (who was then 12-4) was 8. The was twice as old as Sam (who was then 8 - 4) who was 4.

Four years from now Sam (will be 8 + 4) at 12, will be three-quarters of Jane's (who will be 12 + 4) age of 16. Correct answer is 12.

User Avatar

Wiki User

10y ago
This answer is:
User Avatar
More answers
User Avatar

AnswerBot

3mo ago

Let's denote Jane's current age as J and Sam's as S. From the first statement, we have J-4 = 2(S-4). From the second statement, we have S+4 = (3/4)(J+4). Solving these two equations simultaneously, we find that Jane is currently 24 years old.

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Four years ago Jane was twice as old as Sam. Four years from now Sam will be three-fourths of Jane's age. How old is Jane now?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Jamar is four times as old as josh In twice years he will be twice as old as Josh How old is Jamar?

Jamar is four times as old as Josh. In 20 years he will be twice as old as Josh. How old is Jamar?


Frank is 15 years younger then John. In 5 years John will be twice as old as Frank. How old will Frank be in four years?

In four years.. Frank will be 14.


Jamar is four times as old as josh In 20 years he will be twice as old as josh how old is Jamar?

Jamar is four times as old as Josh. In 20 years he will be twice as old as Josh. How old is Jamar?


Can the president be elected to a six year term of office?

No, four years, twice is the maximum.


Your father is four times as old as you are In 20 years he will only be twice as old as you are How old are you now?

You are 10 years old


Helen is thirteen years old. Helen's father is four years more than twice her age?

4+(2X13)


Raju is 15 years younger then Baiju In 5 years Baiju will be twice as old as Raju How old will Raju be in four years?

12


Jamar is four times as old as Josh. In 20 years he will be twice as old as Josh. How old is Jamar?

He is 40 years old.


What happens once in a second twice in a minute four times in a hour but never in a million years?

a heartbeat!!


abdella is 15 years younger than ayele . in 5 years ayele will be twice as old as abdella how old will abdella be in four years pdf?

35


John is twice as old as his brother Four years ago he was four times as old as his brother Find their present ages?

The ages are 8 and 4


John is 4 years older than Tim. 4 years ago John's age was twice Tim's age how old are they?

John is 12, and Tim is eight. Four years ago they would've been eight and four.