Hi dinesh,

did you double post this? Seems there's two threads on this same topic started by the same OP at teh same time! Anyways, I've just copied and pasted the explanation I gave in the other thread. Hope it helps!

we have to translate the English into algebraic expressions that reflect the same meaning.

**Quote:**

five years ago,Beth's age was three times that of Amy

.

How old is Beth today?...Let's call it "B"

Then, how old was Beth five years ago?..."B-5"

Similarly, how old was Amy five years ago?..."A-5"

At this point in time, Beth's age was three times that of Amy. So:

B-5 = 3*(A-5) (1)

Similarly, this sentence:

**Quote:**

Ten years ago ,Beth's age was one half that of Chelsea.

yields:

B-10 = (C-10)/2 (2)

We want to solve for A in terms of C. So, we want to get rid of B. The easiest way is to equate the two equations. But the left-hand sides of each equation are different. So, just subtract 5 from both sides of (1) (OR add 5 to both sides of (2)):

B-5 -5 = 3*(A-5) - 5

B-10 = 3*(A-5) -5

Because B-10 = B-10, we have:

3*(A-5) - 5 = (C-10)/2

Solving for A, we have:

A = C/6 + 5

Choose A!

_________________

Kaplan Teacher in Toronto

http://www.kaptest.com/GMAT

Prepare with Kaplan and save $150 on a course!

Kaplan Reviews