In xy-plane, Y = ax^2 + bx + c, does the graph intersect with X axis?1) a > 02) c < 0 … [Read more...] about DS – Quadratic, Parabola, and Inequalities
GMAT DS
Descriptive statistics – Standard Deviation
If m is the arithmetic mean (average) of 4 integers a, b, c, and d and s is the standard deviation of the 4 integers and s = , then is s > 0?(1) m > a(2) a + b + c + d = 0Solution:s will be zero only in two instances: (i) when all the elements in the set are the same, or (ii) the set contains only one element, which in this case is not possible. So, we need to check whether a, … [Read more...] about Descriptive statistics – Standard Deviation
GMAT Number Properties DS question
Number Properties is an often tested area as far as Data Sufficiency is concerned. Here is an interesting question. Question Is the two digit positive integer P a prime number? 1) P + 2 and P – 2 are prime. 2) P – 4 and P + 4 are prime. Statement (1): P + 2 and P – 2 are prime. One out of 3 consecutive odd integers, (P - 2), P, and (P + 2) will definitely be a … [Read more...] about GMAT Number Properties DS question
GMAT Statistics Practice – Median
Descriptive Statistics that includes mean, weighted mean, median, standard deviation and range is a GMAT favorite. At times it becomes "virulent" in its data sufficiency avatar.Here is a medium difficulty DS question from Descriptive Statistics:DirectionsThis data sufficiency problem consists of a question and two statements, labeled (1) and (2), in which certain data are … [Read more...] about GMAT Statistics Practice – Median
Data Sufficiency : A Quick Overview
GMAT Data Sufficiency I personally love the 'Data Sufficiency' section - because it is fun to solve them ! Broadly two reasons (1) It probably may not involve as much rigorous mathematical solving and (2) Each problem is a field of landmines that the examiner has laid for the student. I have a feeling that even for the test setter, the data sufficiency section is the … [Read more...] about Data Sufficiency : A Quick Overview