Mrs. Brown is 20 years old than her daughter.Five years ago,she was 3 times as old as her daughter.How old is her daughter? Can u tell me please Thank You

Sri

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- Mar 30th 2008, 03:36 PM #1

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- Mar 30th 2008, 09:16 PM #2
Age of Mrs. B

**today**: y

Age of the daughter**today**: x

From the question you know:

$\displaystyle x+20=y$

$\displaystyle y-5=3(x-5)$ ..... That's the situation 5 years ago. Be aware that the daughter was 5 years younger too!

This is a system of simultaneous equations. Solve this system of equations for x and y. (Use substitution method here)

I've got: (x, y) = (15, 35)

- Mar 31st 2008, 09:10 AM #3
$\displaystyle B = Mrs. Brown$

$\displaystyle D = Daughter$

$\displaystyle D+20 = B$

$\displaystyle 3D = B$

$\displaystyle D + 20 = 3D$

$\displaystyle 20 = 2D$

$\displaystyle 10 = D$

But this situation was 5 years ago so...

$\displaystyle D + 5 = Age$

$\displaystyle 10 + 5 = 15$