## LSAT Interact Course Material 3D Ordering

AlexY297
Vinny Gambini

Posts: 19
Joined: September 26th, 2018

### LSAT Interact Course Material 3D Ordering

Hello this is in regards to the Lesson 3 on 3D Ordering Set Pohl Children Problem PT 39 S1 G3 question 15 if Theo was born after Will was born, then how many sequential orderings of the children from firstborn to lastborn, are possible?

I am unsure what the question is asking. Upon seeing how the approach was, how many times Theo was born after Will in frame #1 and #2 was each one time. Total was 2.

Can you explain how to approach such questions when the wording seems odd?

Thank you,
Alex

ohthatpatrick
Atticus Finch

Posts: 4303
Joined: April 01st, 2011

### Re: LSAT Interact Course Material 3D Ordering

A sequential ordering means, "Who's first? Who's second? Who's third? ....etc."

We don't care about specific positions; we care about relative positions.

If these were the dates of my kids' births:
Zazz: 2014
Plops: 2016
T-bone: 2018

Then Zazz was my firstborn, Plops my mischievous middle child, and T-bone will always be the baby of the family.

If we switch the dates,
Zazz: 2015
Plops: 2017
T-bone: 2018
it's still the same sequential ordering. The same person is first, second, third.

So Q15 is asking if W - T, then how many possible sequences of kids are possible.

We end up having these two possible scenarios:
Z S x U W x T
x S x U Z W T

Z - S - U - W - T is one sequential ordering of kids, from firstborn to lastborn.
and
S - U - Z - W - T is the other.

Does that make sense?

You were asking for advice on how to approach odd wording: you have to ask yourself questions about what words mean.
"What is a sequential ordering?"
"What is a sequence?"
"What is an ordering of children from firstborn to lastborn?"
"Can I think of an example? Do I know MY family's sequential ordering of children from firstborn to lastborn?"

Ultimately, the weird moments of the test are by definition beyond the purview of advice. They're weird BECAUSE they're new, and because we don't have a preconceived plan for, or familiarity with, them. We just have to embrace the challenge, think flexibly, and read carefully.

They're mean.