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.

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 »

In a certain sequence of 8 numbers, each number after the first is 1 more than the previous number. If the first number is –5, how many of the numbers in the sequence are positive?

In a certain sequence of 8 numbers, each number after the first is 1 more than the previous number. If the first number is –5, how many of the numbers in the sequence are positive? A. None B. One C. Two D. Three E. Four Correct Answer: C Full explanation coming soon. Send us a

In a certain sequence of 8 numbers, each number after the first is 1 more than the previous number. If the first number is –5, how many of the numbers in the sequence are positive? Read the Full Article »

In the correctly worked addition problem shown, P, Q, R, and S are digits. If Q = 2P, which of the following could be the value of S?

   3P5 +4QR ––––––––    8S4 In the correctly worked addition problem shown, P, Q, R, and S are digits. If Q = 2P, which of the following could be the value of S? A. 3 B. 4 C. 5 D. 7 E. 9 Correct Answer: A Full explanation coming soon. Send us a note if you’d like this added to the express

In the correctly worked addition problem shown, P, Q, R, and S are digits. If Q = 2P, which of the following could be the value of S? Read the Full Article »