Practice Questions Chat

Hi guys, please give this one a shot: survey-conducted-at-city-club-gathered-the-following-information-425050.html?fl=notifications#p3343127

I’ve talked to friends and they say the Free Official mocks have the exact same algorithm as the Original exam

From a group of J employees, K will be selected, at random, to sit in a line of K chairs. There are absolutely no restrictions, either in the selection process nor in the order of seating — both are entirely random. What is the probability that the employee Lisa is seated exactly next to employee Phillip?

(1) K = 15
(2) K = J

In this DS question can anyone explain the calculation. How do I solve for the numerator?

Have you check this topic: https://gmatclub.com/forum/from-a-group ... 93411.html ?

Hello All,
I had a small question in the quant section while doing probability I can across this following example, I am not sure how did we reach the conclusion that P(A and C) < P(A)
I.e 0.23

Here is the solution in the example:

Example:
In an experiment with events A, B, and C, suppose P (A) = 0.23, P (B) = 0.40, and P(C) = 0.85.
Also suppose events A and B are mutually exclusive, and events B and C are independent. Since
A and B are mutually exclusive, P(A or B) = P(A) + P(B) = 0.23 + 0.40 = 0.63.
Since B and C are independent, P(B or G) = P(B) + P(C) -P(B)P(C) = 0.40 + 0.85 - (0.40)(0.85)
= 0.91.
P(4 or G) and P(4 and C) can’t be found from the information given. But we can find that
P(A) + P(G) = 1.08 > 1. So P(A) + P(C) can’t equal P(A or C), which like any probability
must be less than or equal to 1. This means that A and C can’t be mutually exclusive, and that P(Aand C) ≥ 0.08.
• Since An Bis a subset of 4, we can also find that P(A and C.) ≤ P (A) = 0.23.?
And Cis a subset of A U C, so P(A or C) ≥ P(C) = 0.85.
Thus, we’ve found that 0.85 ≤ P(A or C) ≤ 1 and that 0.08 ≤ P(A and G) ≤ 0.23.
55

I did check out but i couldn’t understand the solutions provided. Especially how to solve for the numerator

first statement doesn’t give any data about J so insufficient.
second statemnt doesn’t give any particular number so even if they are equal, the chances of sitting them together is 1 but we dont have denominator
combing both equations tells us that if lisa is not there then rest 14 people can sit on 14 chairs. but for lisa to sit with philip, it will only be possible in 1 way so 1/total
so c-(1/15)

2 ways*

Hi all, I am appearing for the Focus Edition on Feb 2nd (day after). I can say I have given close to 3 months of full-fledged prep and used a couple of sources (in addition to OG and the GMAT Club forums). My target score is 655 and above (90th percentile and beyond). However, I am struggling to make sense of my mock scores.

For anyone who’s kind enough to take out the time - would you mind looking at the score breakdown below and help speculate as to why my verbal and quant scores (and hence, the overall) keep stagnating around 555-575? As for DI, I know DS is a weak area for me, but besides that I’m clueless.

PS - the odd 535 and 545 in Magoosh was a bad, below-average attempt on my part due to stress and lack of sleep. So discounting that a little for now.

Any advice/recommendations would be highly appreciated. Thank you so much in advance!

These are GmatPrep mock exams?

Yes, all official mocks. And one Magoosh practice test.

What are the question numbers you’re doing wrong in each sections?

I have not done this analysis yet, but I tend end each section okay. Sometimes in Quant, the start is a little off and overall I’m getting around 9-10 wrong. Quant has always been my weak area. . .

You are doing your initial questions wrong.

Yes, this is true for Quant and possibly for DI as well. But in Focus, getting the first 3/4 questions wrong is NOT going to get you heavily penalized, right? This was a major feature in Classic.

Does it still matter in Focus then?

When did the algorithm change?

It’s still a CAT.

I know it is still adaptive, but was under the assumption that the Focus edition was not looking at the sequence number as much. Classic is known to be unforgiving for messing up the first 10 questions or so, guess this could be the case for Focus as well.