'' what are their ages now''.

[eddy2017]

To browsers of the forum ( I am one avid browser), i wanna post this problem and a new method with a chart that helps focus a little bit more. let's see what the tutors think.

''A sister is 8 years older than her brother. After 3 years the sister's age will be twice the age of her brother's. what are their ages now''.
I'll set up this table

age now ----------------------------after three years

brother x -----------------------------x + 3
sister x+8 ---------------------------- x+8 + 3

you see how the charts helps focus.
now, the problem says, after three years the sister's age will be twice his brother's
just have to look at the table
sister's age after three yrs = x + 8 + 3
will be twice her brother's
so
x+8+3 = 2(x+3) and then from this point on you will just be solving the equation.
now we have to solve for x
x+8+3 =2x+6

x+11=2x+6 combining like terms
-6 + 11 = 2x-x
5=x
x=5
now that we have the age of the brother, it is easy to find out the age of the sister.

look back at the table and you will see that the age of the sister now is
x+ 8 replace x with 5
=13
the sister is 13 yrs old
his borther is 5 yrs old
for this basic age problem i have found that drawing a table and let the data in the problem fill it out has been a great help
let see what the tutors say
thanks,
eddy

 

[nasi112]

The title is the whole question. This is beautiful

 

[eddy2017]

The title is the whole question. This is beautiful

Nasi, yes, you're right, sorry about that . I think It can be fixed by the mods
Thank you for comment ?

i tried and still had time to edit it. thank you for the heads up

 

[nasi112]

Hi eddy. I agree with you about the chart. It helps to solve the problem quickly. It is similar to the time line I used to do to solve some Finance problems. With the time line you can go back and forth without getting lost.

 

[eddy2017]

Thanks for commenting nasi. Appreciate that. like you well say, keeps me from getting lost going back and forth all over the paper.