GMAT Navigator

[SebastianY283]

How do I upgrade from GMAT Navigator Basic to the full version?

[StaceyKoprince]

Hi! You can add Navigator to your shopping cart on this page:
https://www.kaptest.com/gmat/practice/adaptive-qbank

It's the third option on the right. (And there's a sale on right now through the end of May—20% off. )

Happy studying!

[SebastianY283]

Hi Stacey, I have all the books a la carte (All the Quant, All the Verbal, IR, FOV, FOM, Advanced Quant) which I believe I have registered individually on Atlas. Does this give me access to the full version of Navigator by right or do I actually need to purchase an upgrade? I emailed support a few days ago but still no response. I also have other issues that I need help with. May I have your email so I can contact you?

[SebastianY283]

Hi Stacey are you there?

[StaceyKoprince]

Hi! For future reference: I answer questions twice a week, on Mondays and Thursdays. (Unless there's a holiday, in which case it might change by a day, or when I'm on vacation, in which case another teacher will sub for me.)

If you buy the All the GMAT book set via the main account on Amazon (that is, not via a third-party reseller), then you get a special one-time-use code that also gives you access to certain online resources (full Navigator, practice exams, and so on). That's a higher-priced product in general, though, to also account for the online resources.

If you have bought the books individually or if you buy the set used or via a third-party reseller, then those purchases wouldn't include the online resources.

I'm sorry for the delay in a reply to your email. We're having some issues with our techsupport@ email address, so if you used that, please resend your question tomake_clickable_callback(MAGIC_URL_EMAIL, ' ', 'gmat@manhattanprep.com', '', ''). Alternatively, I'd recommend the live chat feature on our site, which is staffed M-F during standard business hours based on the US eastern (GMT–5) time zone.

I can't actually provide support for any access or resource issues myself, sorry—I don't have access to any account info, etc. I'm really just here as a teacher to talk about the test content and strategy.

If you haven't heard back yet, I would both send to the gmat@ email and try the live chat feature. And if you have any more questions on study strategy / that side of things, let me know here—I'll be back on Monday!

[SebastianY283]

For OG 2022, PS 181, in your solution, the correct formula should be Total = A + B + C - AB - AC - BC + ABC and not -2ABC as written.

[StaceyKoprince]

The formula is correct as written: Total = Group A + Group B + Group C – (AB) – (AC) – (BC) – 2(ABC)

Group A includes everyone in Group A, not just the "Group-A-only" people, so Group A does include the count of people who are in the subgroups AB, AC, and ABC. Ditto for Groups B and C. You might have been reading it as "People in Group A only" rather than "Everyone in A, even if they're also in other groups"?

Just in case that last sentence doesn't clear things up:

Because Group A includes everyone in that group, the overlap needs to be subtracted out. For example, someone who is in Group A and in Group B would be counted twice (once in Group A and once in Group B). The – (AB) part of the equation subtracts out the one "extra" count, so that these people are still included once, but not twice / not the extra time.

Likewise, someone who is in Group A, B, and C would be counted three times (once in Group A, once in Group B, and once in Group C). The – 2(ABC) part of the equation subtracts out the two "extra" counts, so that they are counted only once, not three times.

(You can also write the formula using OnlyA, etc, for the groups—then the formula becomes Total = OnlyA + OnlyB + Only C + AB + AC + BC + ABC. Using this formula, nobody has been counted extra times in OnlyA, OnlyB, and OnlyC. But in the given problem, Groups A, B, and C are given by total value, not OnlyA, etc, so the first version of the equation, above, is the easier one to use.)

For this particular problem, the ABC part of the equation didn't matter (because the value is 0). But here's how that would play out on a problem that had a non-zero positive value in that position:

A group of people are eating fruit. Everybody eats at least one of apples, oranges, and bananas.
20 eat apples
25 eat oranges
30 eat bananas

3 eat apples and oranges
4 eat apples and bananas
5 eat oranges and bananas

6 eat apples and oranges and bananas

How many people ate either apples or oranges or both? (Ignore bananas)
(1) 20 people eat apples and 25 eat oranges, but 3 of those folks were counted twice (in the apples group and in the oranges group). So, subtract out one count of those 3 folks to get rid of the double-count: 20 + 25 – 3 = 42 people who ate either apples or oranges or both.

(2) You can do the same math for:
— either apples or bananas or both: 20 + 30 – 4 = 46
— either oranges or bananas or both: 25 + 30 – 5 = 50

(3) How many people total are in the entire group?
We still need to subtract out the double-counts, as shown in the prior "smaller" versions of the question, but now we also need to subtract out the triple-counts as well—everyone in group ABC has been counted three times each (once in each group), so strip out 2 of those 3 counts:
Total = Group A + Group B + Group C – (AB) – (AC) – (BC) – 2(ABC)
Total = 20 + 25 + 30 – 3 – 4 – 5 – 2(6)
Total = 75 – 3 – 4 – 5 – 12
Total = 75 – 24 = 51 people in the group

[SebastianY283]

For me when I subtracted AB, AC and BC, ABC are also included so it was subtracted 3 times so I needed to add ABC 1 more time to make the final subtraction twice.

I think I understand your solution though. You are treating those in the AB group as those in A and B but not C. I treated those as possibly including C as well. For example if A = people that ate apples, B = people that ate bananas and C = people that ate oranges, I think your AB means those that ate apples and bananas and not oranges while for me I treated AB as those that ate apples and bananas (and may include oranges as well).

[StaceyKoprince]

Ah, yes, exactly. AB = those in A and B but not in C, while ABC = those in A, B, and C. Glad we figured it out.

[StaceyKoprince]

[Edited to add: The below was in response to a spammer who posted a normal comment, and then edited the response to spam after I responded. Yes, we check and, yes, we will find and delete your edited-to-spam post and ban you. So please don't waste your own time or ours! ]

You are very welcome!