Age problem - Page 71: #76: OG 11th ed.

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Age problem - Page 71: #76: OG 11th ed.

by AleksandrM » Sat May 24, 2008 4:27 pm
Today Rose is twice as old as Sam and Sam is 3 years younger than Tina. If Rose, Sam, and Tina are alive 4 years from today, which of the following must be true on that day?

I. Rose is twice as old as Sam.
II. Sam is 3 years younger than Tina.
III. Rose is older than Tina.

A) I only
B) II only
C) III only
D) I and II
E) II and III

I am not looking for the answer. I am looking for the logic behind the answer. I read the logic in the OG, and everything is clear to me until the very last bit.
Source: — Problem Solving |

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by wawatan » Sat May 24, 2008 4:55 pm
hope this helps
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by AleksandrM » Sun May 25, 2008 5:23 am
wawatan, I pretty much did what you did... and, my friend, we are both WRONG!!! The answer is II alone. For the life of me, I cannot understand how this is possible!!!

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by ksh » Sun May 25, 2008 8:13 am
Hi AleksandrM,

We are asked to calculate their age 4 years hence. so, by given condition

1. R=2S it will not hold true after 4 years
2. S=T-3, It will hold true after 4 years and is TRUE
3. R=2S => R=2(T-3)
=>R=2T-6, this will also not hold true after 4 years

Above can be verified by plugging in nos.

Hence, ans is b.

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by wawatan » Sun May 25, 2008 2:37 pm
this one should be correct.
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