GMAT Ninja Quant Ep 3: Quadratics

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  • Опубликовано: 6 фев 2025

Комментарии • 30

  • @m_helal433
    @m_helal433 Месяц назад +5

    The video is so helpful and I find these hints very useful to me:
    * Read the question twice-first for the big picture and then for specific details.
    ** For cost problems, use clear variables (e.g., lowercase for prices, uppercase for quantities).
    *** Simplify units (e.g., pennies instead of dollars) for better handling of integer equations.

  • @nabilfarooqi7249
    @nabilfarooqi7249 Месяц назад +5

    helpful rule on #3 - since we can see that 3^16 - 1 is simply the prior number to 3^16, there is a rule that states consecutive integers never share prime factors. Since 3^16 has prime factor 3, we can conclude 3^16 - 1 does NOT contain prime factor 3. And 24 is the only ans choice that contains 3 as a prime factor (or 24 is the only choice that is a multiple of 3)

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  27 дней назад

      Very nice! There are always multiple paths to the correct answer, and more tools we have in our toolkit (or maybe rules in our rulekit), the more options we have for solving problems. This rule about consecutive integers and their prime factors may not apply to very many GMAT Quant questions, but in this case it's a good tool for the job and answers the question quickly. Well done!

  • @RedditPublisher-69
    @RedditPublisher-69 23 дня назад

    I haven't had my head active in math for 3 years as my degree didn't required maths but at the last question due to this awesome guidance I was able to solve Q7 in 15 sec i.e. in 2-steps , I cross multiplied the 1st and 2nd term it eliminated ✓3 on top and left me with 2✓5 in the numerator and then in the denominator I used (a+b)*(a-b)= (a^2-b^2) formula and was left with 2 cancelled the 2 on to and bottom and then squared the ✓5 and got 5 which was the correct answer

  • @hugodavis6108
    @hugodavis6108 24 дня назад +4

    Love this video thanks guys
    Surely an easier way to do Qu6 is to isolate the radical to one side and then square? Pls lmk if this method would run into trouble in a different question of this type:
    x = 3 + sqrt(2)
    x - 3 = sqrt(2)
    Now square both sides:
    (x - 3)^2 = 2
    Expand:
    x^2 - 6x + 9 = 2
    Make equal to zero:
    x^2 - 6x + 7 = 0 => answer choice B

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  23 дня назад +3

      There are many paths to the correct answer, and that's a terrific one!
      'Easy' is in the eye of the beholder, and different test-takers will see different relationships between the terms, which will lead them to different paths to the solution. This approach is elegant and shouldn't get you into trouble.
      Thanks for pointing out the possibility!

    • @BuffBuddiesLounge
      @BuffBuddiesLounge 4 дня назад +2

      this is such a good way to tackle it

  • @ooyoo8510
    @ooyoo8510 21 день назад

    This instructor is excellent!

    • @alexcotton1180
      @alexcotton1180 8 дней назад

      Thanks so much! Glad you found the video helpful -- happy studying!

  • @nexmat26
    @nexmat26 Месяц назад +2

    In Q1, can we proceed like this:
    w(w-1)=z(z-1)
    Simply it further:
    w^2-z^2=w-z
    (w-z)(w+z)=(w-z)
    Cancel (w-z) both sides which gives:
    (w+z)=1
    A simpler way than calculating their individual values.

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  27 дней назад

      Yes, you can proceed in that way! There are always multiple paths to the correct answer.
      When you spot a useful relationship and see a path to the answer, go for it!

  • @aryannair6147
    @aryannair6147 Месяц назад +1

    A very helpful video... I would just like to know about the level of difficulty of each question as in solving the 5 th question is around how much marks . Would be grateful if we could get that

  • @anushridicholkar2961
    @anushridicholkar2961 12 дней назад

    32:11 yes Imma remember this on my exam day!

  • @leonardobressan7727
    @leonardobressan7727 15 дней назад

    very interesting video, thanks a lot!
    but about Q6.. if we know that one root is 3+sqrt(2) then can I say that the other one is 3-sqrt(2)? then solve it as x^2 - (sum of the roots)x + (product of the roots) = 0.
    sum = (3 + sqrt(2)) + (3 - sqrt(2)) = 6
    prod = (3 + sqrt(2))(3 - sqrt(2)) = 3^2 - (sqrt(2))^2 = 9 - 2 = 7
    put together = x^2 - 6x + 7 = 0.
    does this assumption make sense?

  • @prernaagrawal6217
    @prernaagrawal6217 Месяц назад

    Hi, i wanted some guidance over studying through these videos. I found some of the questions challenging in here and would definitely want to revisit them. However, I’m not sure what would be the right flow of coming back to these questions. I dont want to indulge in the other topics too much that i completely forget about the topic but at the same time i want to give myself enough time to forget the exact solution path followed when i first go through these videos.
    In essence, if I’m just starting out my GMAT focus preparation through your channel, how should I plan on studying the quant, verbal and data insights portions together?

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  27 дней назад

      It's a good idea to let some time go by and approach an old question as though it were new. And of course you'll need *all* the Quant topics on test day! As you work on one topic and then another, you're adding that topic to your abilities -- you aren't leaving one topic in order to move on to another. Mixed sets will help you keep 'old topics' fresh.
      For an overall approach to all three sections of the GMAT, try the GMAT Ninja's Thirteen Week Self Study Guide on GMAT Club.
      Hope that helps -- and happy studying!

  • @alfredtindjau6327
    @alfredtindjau6327 Месяц назад

    Hello, thank you for the great videos! I trchnically “should” be able to get nearly all, but when I was doing them, I did not think of a more effective method. Perhaps it’s just getting familiar with these questions? :)

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  27 дней назад

      Getting familiar with GMAT Quant -- what is asks for and how it asks for it -- is definitely part of prep. Every Quant question is different from every other Quant question -- and it's also similar to other Quant questions. The more questions you meet, the harder it is for the GMAT to surprise you. (But it *will* surprise you!)

  • @alfredoherrera7812
    @alfredoherrera7812 Месяц назад

    These questions about quadratics still exists in the new gmat?

  • @mdaetesamuddin8657
    @mdaetesamuddin8657 13 дней назад

    thank u

  • @Susiefluffyhead
    @Susiefluffyhead 17 дней назад

    Actually, in Q5 I think it should be able to solve without have to multiply the price into hundreds but I don’t know why I can’t solve it without your tricks or am I miscalculate anything?

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  15 дней назад

      You certainly can keep this question in dollar terms and say Philip and Colin each have $3 and the price difference is $0.01. That will work -- be sure to keep track of the decimal point!
      Many test-takers find integers more straightforward than decimals, and the question works in exactly the same way if we think in terms of cents and say Philip and Colin each have 300¢ and the price difference is 1¢.
      This kind of restatement isn't really a trick; it's a matter of expressing the question's information in the form that will be most useful to us.

  • @DylanIE_
    @DylanIE_ Месяц назад

    In Q3, why is -1.5 the answer? What makes it less possible than the other 2? I originally thought the question was asking about which of the answers was it least likely to be and so worked out which of the answers is the furthest away by absolute value.
    Even though that doesnt make much sense, but I think I am still incredibly confused by what the question is asking. How can a possible answer be any less possible than another? If it was asking about the lowest number, shouldnt it have asked whats the "lowest" possible solution rather than whats the least possible? I feel like those two things are very different.

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  Месяц назад +1

      This phrasing doesn't refer to the possibility of a number or how likely that number is to be. Instead, it refers to how far to the left (lesser) or right (greater) a number appears on a number line.
      While it might seem confusing, the GMAT uses "least possible" when referring to the number furthest to the left on a number line in several of their questions. I've put a link to one example from the GMAT Official Guide at the bottom of this message so you can see it used in an official question.
      In this question, the possible solutions to the equation are -3/2, 0, and 2. Of those, the least is -3/2, so the "least possible" solution is -1 1/2, meaning (B) is the answer to this question.
      I hope that helps!
      gmatclub.com/forum/if-the-range-of-the-six-numbers-4-3-14-7-10-and-x-is-12-what-is-104739.html

    • @TuanDungNguyen-wo5yj
      @TuanDungNguyen-wo5yj 26 дней назад

      @@GMATNinjaTutoring I still didn't get the explanation... If you present a number line with 0 at the center, shouldn't 2 be further on the right (greater) than -1.5 is to the left (lesser)?

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  15 дней назад

      @@TuanDungNguyen-wo5yj Yes, you're absolutely right, but let's take a close look at the wording of the question. We're asked to find the "least possible solution" of the equation. As shown in the video, the possible solutions of the equation are -1.5, 0, and 2. Of those, the least is -1.5, which is why this is the answer to the question.
      I hope that helps!

  • @shobhitbajiya5319
    @shobhitbajiya5319 Месяц назад

    In the 6th question, why does it have to be a -6x?

    • @GMATNinjaTutoring
      @GMATNinjaTutoring  Месяц назад

      If one of the roots of a quadratic equation is 3 + sqrt(2), then we know that x^2 = 11 + 6*sqrt(2) as John Michael showed in the video. Each of the answer choices has a zero on the right-hand side, so we need x^2 plus some number of xs plus some numbers to equal zero.
      Since the number terms don't have any square roots, we need the x-term to subtract 6*sqrt(2) from the x^2 to make sure we have zero square roots on the left-hand side. The way we can do that is to use -6x in the equation we're generating to give x^2 - 6x plus a number.
      I hope that helps!

    • @hugodavis6108
      @hugodavis6108 24 дня назад

      see my answer method above i think it's much simpler