I19-03

Question

Rahul, Samuel, Tony, Uday, and Xavier met for a reunion, 15 years after graduating. During the reunion, they observed that only Rahul and Tony had gained significant weight, while the other three had remained lean. To celebrate, they are considering going on a popular swing ride in town.Due to combined space and weight constraints, the swing could accommodate a maximum of three people, with no more than one person of heavy build.The friends had the following personal conditions for going on the swing:
 
• Uday would ride only if Xavier also rides.
 
• Xavier would not ride if Tony is on the same ride.
 
• Samuel would ride only if he would be one of exactly three people riding.

Bunuel · Answer

Official Solution:

• Rahul is not guaranteed. A valid group like Samuel, Xavier, and Uday excludes him.
 
• Samuel is not guaranteed. A valid group like Rahul, Xavier, and Uday excludes him.
 
• Tony is not guaranteed. A valid group like Samuel, Xavier, and Uday excludes him.
 
• Uday is not guaranteed. A valid group like Samuel, Xavier, and Rahul excludes him.
 
• Xavier is guaranteed. If he’s excluded, Uday is also out. That leaves only Samuel, Rahul, and Tony—but Rahul and Tony are both heavy, which isn’t allowed. So every valid group must include Xavier. For example, Rahul, Xavier, and Uday is a valid group.

Correct answer:

If exactly three of the five friends were to go on the swing ride, and all constraints were met, who is guaranteed to be one of the three?

"Xavier"

Bunuel · Answer

This MSR question and its solutions have been completely revised and improved.

aditsatt · Answer

I don’t quite agree with the solution. Rahul is heavy, so three people wouldn't be possible - Answer should be Samuel who wouldn't ride without 2 other people

Bunuel · Answer

That’s not correct - the question asks who is guaranteed to be in  any  valid group of 3, assuming all constraints are met.

Rahul being  heavy  doesn’t force him to ride - it just limits the group options.

But Samuel is  not  guaranteed either - he can be left out if there’s a valid group like Rahul, Xavier, and Uday.

Xavier  is  guaranteed because without him, Uday can’t ride (given constraint), so you’re left with Samuel, Rahul, and Tony, but Rahul and Tony are both  heavy , and they can’t ride together.

That’s why the answer is  Xavier,  not Samuel.

rsrini · Answer

I like the solution - it’s helpful.

VidishaSRoy · Answer

I like the solution - it’s helpful.

Katyshka · Answer

I like the solution - it’s helpful.

ritik156 · Answer

"Samuel would ride only if he would be one of exactly three people riding." I could not understand this preference.

Bunuel · Answer

It means Samuel will only ride if all 3 seats are taken. If fewer than 3 people go, he won’t ride.

maioresodit · Answer

I did not quite understand the solution. Uday is not guaranteed. A valid group like Samuel, Xavier, and Rahul excludes him.

Here, I did not understand why Uday is not guaranteed as if Xavier is included then Uday must be included?

maioresodit · Answer

• Uday is not guaranteed. A valid group like Samuel, Xavier, and Rahul excludes him.

In this point, I did not understand how Uday is not guaranteed as if Xavier is included then Uday must be included as well.  
 Please clarify my doubt.

Bunuel · Answer

You’re mixing up the direction of Uday’s condition.

Uday would ride only if Xavier rides.
 
That means: if Uday rides, then Xavier must be there.
 
It does  not  mean: if Xavier rides, then Uday must be there.

So Xavier can ride without Uday. Uday cannot ride without Xavier. That is why Uday is not guaranteed.

maioresodit · Answer

ohh I see now, thanks for pointing out my mistake.

sunshineeee · Answer

Hi Bunuel, could u explain how to approach this question better to finally can come up with this mapping scenario?
My answer is initially Samuel simply i got trap because i did not calculate the scenario if case like S or U might also constraint and leave X to be the only one who own no constraint.

Thanks

Bunuel · Answer

A solution I cam up with is HERE , additionally I tired elaborating on the question in the thread above. You can find alternative solution here: https://gmatclub.com/forum/rahul-samuel ... l#p3553368 Happy to address any specific doubt you have.

I19-03

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