Andrew Geller

Andrew Geller is a top GMAT tutor based out of New York City. Throughout his career he has successfully taught people from many different backgrounds, countries, and starting scores.

If the average (arithmetic mean) of the four numbers 3, 15, 32, and (N + 1) is 18, then N =

If the average (arithmetic mean) of the four numbers 3, 15, 32, and (N + 1) is 18, then N = A. 19 B. 20 C. 21 D. 22 E. 29 Correct Answer: C Full explanation coming soon. Send us a note if you’d like this added to the express queue! You’ll find tons of practice questions, explanations […]

If the average (arithmetic mean) of the four numbers 3, 15, 32, and (N + 1) is 18, then N = Read the Full Article »

During a recent storm, 9 neighborhoods experienced power failures of durations 34, 29, 27, 46, 18, 25, 12, 35, and 16 minutes, respectively. For these 9 neighborhoods, what was the median duration, in minutes, of the power failures?

During a recent storm, 9 neighborhoods experienced power failures of durations 34, 29, 27, 46, 18, 25, 12, 35, and 16 minutes, respectively. For these 9 neighborhoods, what was the median duration, in minutes, of the power failures? A. 34 B. 29 C. 27 D. 25 E. 18 Correct Answer: C Full explanation coming soon.

During a recent storm, 9 neighborhoods experienced power failures of durations 34, 29, 27, 46, 18, 25, 12, 35, and 16 minutes, respectively. For these 9 neighborhoods, what was the median duration, in minutes, of the power failures? Read the Full Article »

In a set of 24 cards, each card is numbered with a different positive integer from 1 to 24. One card will be drawn at random from the set. What is the probability that the card drawn will have either a number that is divisible by both 2 and 3 or a number that is divisible by 7?

In a set of 24 cards, each card is numbered with a different positive integer from 1 to 24. One card will be drawn at random from the set. What is the probability that the card drawn will have either a number that is divisible by both 2 and 3 or a number that is

In a set of 24 cards, each card is numbered with a different positive integer from 1 to 24. One card will be drawn at random from the set. What is the probability that the card drawn will have either a number that is divisible by both 2 and 3 or a number that is divisible by 7? Read the Full Article »

Which of the following statements must be true about the average (arithmetic mean) and the median of 5 consecutive integers?

Which of the following statements must be true about the average (arithmetic mean) and the median of 5 consecutive integers? I. The average is one of the integers. II. The median is one of the integers. III. The median equals the average. A. I only B. II only C. III only D. I and II

Which of the following statements must be true about the average (arithmetic mean) and the median of 5 consecutive integers? Read the Full Article »

At the start of an experiment, a certain population consisted of 3 animals. At the end of each month after the start of the experiment, the population size was double its size at the beginning of that month. Which of the following represents the population size at the end of 10 months?

At the start of an experiment, a certain population consisted of 3 animals. At the end of each month after the start of the experiment, the population size was double its size at the beginning of that month. Which of the following represents the population size at the end of 10 months? A. 2³ B.

At the start of an experiment, a certain population consisted of 3 animals. At the end of each month after the start of the experiment, the population size was double its size at the beginning of that month. Which of the following represents the population size at the end of 10 months? Read the Full Article »