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 Data Sufficiency
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
GMAT DS : Number Properties
Number Theory is a big hit with the GMAT test setters, especially when setting Data Sufficiency Questions. Here is a GMAT Data Sufficiency practice question from the Number Properties and Number Theory topic. Directions This data sufficiency problem consists of a question and two statements, labeled (1) and (2), in which certain data are given. You have to decide whether … [Read more...] about GMAT DS : Number Properties