Ace The GMAT - Part1
Apr 23, 2009 Study Skills 2822 Views
This post is specifically for highly self-motivated GMAT aspirants who dream of cracking the GMAT with 700+ scores. They understand that more and more test takers are getting adept at test taking and the competition is getting much stiffer. The Verbal Section tends to take one's score down significantly. The point in case is that how come so many people who use the same material do not manage to score well on this standardized test. Main reasons are lack of stamina, focus and poor time management.
Some tips for Quantitative Number Properties It is extremely critical to understand behaviour of numbers. A good way to understand this is to take the following 7 numbers and understand their properties. Lets put the variable as x. When x = 1/2, x ^ 2 = 1/4, x ^ 3 = 1/8 so on and so forth. Try this for any other positive fraction like 1/3, 1/5 etc. You will get similar results. Property: Whenever is between 0 and 1, x raised to any power greater than 1 will have a value will lower than that of x
Similarly check for properties of 1 / x. If x = 1/2, 1/x = 2. Try this for any other positive fraction like 1/3, 1/5 etc. You will get similar results Property: Whenever is between 0 and 1, reciprocal of x will be greater than x
Similarly try out number properties with x = 2, x = -1/2, x = -2. A savvy GMAT test taker learns these properties just as s/he did during school days for trigonometric ratios, factorization formulae etc. Whenever there is a data sufficiency problem and there is concern regarding the number properties, a high scorer checks for the properties with 7 numbers 0, 1, -1, 2, -2, 1/2 and -1/2 as deemed appropriate. (The author of Ace The GMAT calls it the magic 7 numbers. I totally agree with him on this one)
Another important trick that savvy GMAT test takers use for multiplication is the application of Vedic Mathematics. If you had to say calculate 96 times 47, you would lose some time in calculating this with normal rules of multiplication. Short Cut Method for Multiplying 2 digit numbers 98 x 47 Multiply the units digit of both the numbers i.e. 7 x 8 = 56. Retain 6 in the units digit of the answer and carry forward 5. Then cross multiply the units digit of one number with the tens digit of the other and add the products. In this case it will be (9 x 7) + (4 x 8) = 95. Add the carried forward portion of the previous multiplication i.e. 5 and the result is 100. Retain 0 in the tens place of the result and carry forward 10. Now multiply the tens digit of both the numbers i.e. 9 x 4 = 36. Add 10 to this result and you get 46. Prefix this with the answer and the resulting number is the final answer i.e. 4606.
Seems complicated - trust me its not. Lets try 69 x 29 9 x 9 = 81 Retain 1 in the units place and carry forward 8 (*1 is the answer) (6 x 9) + (9 x 2) + Carry forward portion 8 = 80. Retain 0 in the tens place and carry forward 8 (*01 is the answer) 6 x 2 + Carry forward portion 8 = 20 Prefix this to 81 and the final answer is 2001
Try this with a few numbers and you will love the speed and accuracy with which you can solve problems.
...To Be Continued