In the 7 day sprint before I took the exam for the second time I made sure to start working on harder problems and techniques. I can’t put all the techniques in detail here, but know that if you follow the courses I will reccomend on the next post, you will find these techniques there.
Things I learned for Quant:
- Formula to directly know what is the time it takes machine A and B together to do one unit of work knowing the individual rates of each. (This wasn’t that important as you can derive it algebraically yourself… but sometimes knowing formulas such as this can help).
- Formula to find the sum of all factors of a number
- Formula to find all the trailing zeros on a factorial
- Method to find n of powers of a prime in n!
- In any evenly spaced set, the mean is equal to the median and can be calculated by taking the average (mean) of the 1st term and last term. (This is very important, and you should know it).
- From point 5 it is derived that the sum of all terms on an evenly spaced setis the average * number of terms.
- Sum of first n postive odd integers is n^2
- Sum of first n positive even integers is (n(n+1)).
- % change formula (Sometimes this easy topic can mislead…. careful
- How to factorize a quadratic equation (covered already in previous posts)
- Average “deviation” technique. When adding a new term , the deviation from the mean gets spread on every value on set hence it is easy to know what new average is.
- Weighted average formula to allow you to calculate final new Average given initial average and weightages. This is absolutely ESSENTIAL to solve mixture problems. Check “don’t memorize” mixture videos.
- Alligation formula. This is absolutely ESSENTIAL to solve mixture problems. This alloes you to find ratio of w1 to w2 given the intitial individual averages in iitial mixtures and the final average once mixed.
- Advanced mixture techniques (formula to know final average of A when taking and replacing a quantity X from mixture A+B and replacing it with X of pure substance A, n times.)
- Divisor and Remainder Generalization
- Venn Diagrams & Sets Pro technique (This was on GMATClub Math Book). They are 2 formulas that allow you to solve Venn diagrams super easily. Formula 1: A + B + C – (Sum of Exact 2 overlaps) – 2 (Overlap of 3) + None. And formula 2: A + B + C – (Sum of all two overlaps) + (three of all) + None. To understand these you need to do some problems (you will find them on GMATClub Math bok also).
- Geometric progression sumation of terms formula.
- Diagonal of a cube of side a = root(3)a
Things I learnt from Verbal:
Again, I can’t go in depth in each, but basically if you follow the resources I will put on my next post, you will encounter all this.
- Enther or / neither nor rules
- Collective nounds rules (singular/plural)
- “There ARE a young man and an older woman at the bus stop” is the correct way of saying it
- The sign “;” separates 2 independent clauses on GMAT
- “A number of ____” is plural
- “My brother reserved a table for Janice and me (object)”
- “Janice and I reserved a table (subject)”
- Pronouns must have antecedent, relationship must make sense and no ambiguity allowed.
- Who/whoever – subject in clause
- Whom/whomever – object in clause
- “That” CAN NOT modify people (on GMAT particular rule)
- “Where” CAN MODIFY a location, NOT something abstract (use “in which” for those instead)
- Just as.. so…. is a correct idiom e.g . “Just as an archaeogologist needs a background in art history to evaluate finds of ancient art, so a nautical archaelogist needs specialized knowledge….”
- Not only… X but also Y
- Series of infinitives can use “to” througout or before the first verb only
- Do not omit “other” or “else” whe comparing a noun to a group to which the noun belongs
- Like vs as (very important to learn this as it will most probably appear on the exam)
- Such as / Like (very important to learn this as it will most probably appear on the exam)
- A is different FROM B
- Lay vs lie
- between vs among
- Comparatives vs Superlatives
- If vs whether (another favourite to be tested on GMAT. Learn it)
- Countable vs Uncountable nouns (fewer/many/number vs less/much/amount)
- Instead of vs Rather than
- mistake X for Y
- Paralelism is more important than concision on GMAT (Paralelism is BY FAR one of the most powerful tools you have to crack Sentence correction. Learn it well).
- Use “which” only to refer to the noun immediately precedint it. Never to refer to the entire clause.