Elle, Wahida, Yelli, and Zack stay in the same house.

Question

Elle, Wahida, Yeli, and Zack stay in the same house. Elle is three times older than Yeli. Zack is half the age of Wahida. Yeli is older than Zack.

Select Correct and Incorrect, for what can be definitely concluded to be correct and incorrect respectively, based on the information given above. Make only two selections, one in each column.

ebdsc123 · Accepted Answer

E=3Y..................(i)
Z=1/2 W..............(ii)
Y>Z.....................(iii)
E>Y>Z

therefore
Y=E/3...........from(i)
Because Y>Z 
Therefore E>3Z
and from (ii)
W=2Z
Therefore
E>W

ShilpiAgnihotrii · Answer

My approach was, considered 2 cases:

Case 1: z=10 and y=30 it makes, w=20 and e=90 , so E>Y>W>Z

Case 2: z=20 and y=30 it makes, w= 40 and e=90, so E>W>Y>Z

I dont think there can be any other valid scenarios as per the given condition (Elle is three times older than Yeli. Zack is half the age of Wahida. Yeli is older than Zack.)

In both the above cases, the INCORRECT one is  Wahida is the oldest among the four, (Elle is the oldest)  and the CORRECT is " Elle is older than Wahida." 
Other options may or may not happen based on the considerations above.

Experts can correct/reply in case this needs correction. thanks!

Vivek1707 · Answer

Hi, in the question its mentioned that Elle is 3 times older THAN Yelli. So should it not be written as E = 4y instead of E = 3y ?. I know the answer wouldnt change but I just wanted to clarify.

ShilpiAgnihotrii · Answer

No, its basic maths, e.g. 3 times 4 is 12 not 16. Not sure if I have gotten it correct what you are trying to say.......

Dooperman · Answer

E=3Y ... (i)
 
Z=1/2 W ......(ii)

Y>Z .......(iiii)
This means Max value of Z = Y.

Assume max value of Z=Y Use this in (ii)
Wmax= 2Y
But E=3Y

Hence E>W.

chetan2u · Answer

Let us represent the age of Elle, Wahida, Yeli, and Zack by E, W Y and Z.

Elle is three times older than Yeli. =>  E=3Y 
Zack is half the age of Wahida. =>  W=2Z 
Yeli is older than Zack. =>  Y>Z

Let us see if we can find a relation between W and E.
  E=3Y and Y>Z, so E=3Y = 3(>Z) and surely E>3Z . This makes E the largest, and Z the smallest.

So, depending on Z and Y, W could be 2nd or 3rd largest. 
1. E........Y...W.....Z, =>   when Z=10, W=20, Y=21 and E=63  
2. E....W...Y...Z, =>   when Z=10, Y=18, W=20 and E=54

So the option that gives E>W is correct and the option that gives W>E is incorrect.

Parthkulkarni · Answer

The official answer seems correct.

It says -
Correct: Elle is older than Wahida.
Incorrect: Wahida is the oldest among the four.

So as all of us have deducted that e>w then then that's the correct statement and for incorrect statement too that helps. It helps to tell that w is not greater than ellie

Posted from my mobile device

SKaur3 · Answer

Bunuel  Can you please post a solution to this?

cheshire · Answer

Hope this might help

Given 
 
 Elle’s age E=3Y (three times Yeli’s age Y). 
 Zack’s age Z=(1/2)W = (half Wahida’s age W). 
 Y>Z  
 Show Elle > Wahida 
Y>Z=(1/2)W ⟹ 3Y>(3/2)W ⟹ E=3Y>W.
 Correct statement 
 
 Elle is older than Wahida.  
 Why “Wahida is the oldest” is incorrect 
 
 Because E>W, Wahida cannot be the oldest.

Sonatomar · Answer

Let Zack's age = z

Given:

1. Zack is half the age of Wahida.

W=2Z
2. Yeli is older than Zack.
Y>Z
3. Elle is three times as old as Yeli.
E=3Y

Now compare everyone.

Since

Y>Z

Multiply both sides by 2:

2Y>2Z

But

2Z=W

Therefore

2Y>W

Since

E=3Y>2Y

we get

E>W
 ​

So Elle is definitely older than Wahida.

Elle, Wahida, Yelli, and Zack stay in the same house.

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My Rewards

Correct	Incorrect
		Yelli is older than Wahida.
		Wahida is older than Yeli.
		Elle is older than Wahida.
		Among the four, Yelli is older than only Zack.
		Wahida is the oldest among the four.

GMAT Two-part Analysis (TPA) Questions

­Elle, Wahida, Yelli, and Zack stay in the same house.

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

Elle, Wahida, Yelli, and Zack stay in the same house.