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.

The value of (2⁻¹⁴+2⁻¹⁵+2⁻¹⁶+2⁻¹⁷)/5 is how many times the value of 2⁻¹⁷?

The value of (2−14+2−15+2−16+2−17)/5 is how many times the value of 2−17? A. 3/2 B. 5/2 C. 3 D. 4 E. 5 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 for GMAT Official Guide questions, and strategies on […]

The value of (2⁻¹⁴+2⁻¹⁵+2⁻¹⁶+2⁻¹⁷)/5 is how many times the value of 2⁻¹⁷? Read the Full Article »

For the positive integers a, b, and k, ak||b means that ak is a divisor of b, but ak+1 is not a divisor of b. If k is a positive integer and 2k||72, then k is equal to

For the positive integers a, b, and k, ak||b means that ak is a divisor of b, but ak+1 is not a divisor of b. If k is a positive integer and 2k||72, then k is equal to A. 2 B. 3 C. 4 D. 8 E. 18 Correct Answer: B Full explanation coming soon. Send us a note if you’d like this added to the express queue! You’ll find

For the positive integers a, b, and k, ak||b means that ak is a divisor of b, but ak+1 is not a divisor of b. If k is a positive integer and 2k||72, then k is equal to Read the Full Article »

Each year for 4 years, a farmer increased the number of trees in a certain orchard by 1/4 of the number of trees in the orchard the preceding year. If all of the trees thrived and there were 6,250 trees in the orchard at the end of the 4-year period, how many trees were in the orchard at the beginning of the 4-year period?

Each year for 4 years, a farmer increased the number of trees in a certain orchard by 1/4 of the number of trees in the orchard the preceding year. If all of the trees thrived and there were 6,250 trees in the orchard at the end of the 4-year period, how many trees were in

Each year for 4 years, a farmer increased the number of trees in a certain orchard by 1/4 of the number of trees in the orchard the preceding year. If all of the trees thrived and there were 6,250 trees in the orchard at the end of the 4-year period, how many trees were in the orchard at the beginning of the 4-year period? Read the Full Article »

The light in a restroom operates with a 15-minute timer that is reset every time the door opens as a person goes in or out of the room. Thus, after someone enters or exits the room, the light remains on for only 15 minutes unless the door opens again and resets the timer for another 15 minutes. If the times listed above are the times at which the door opened from 8:00 to 10:00, approximately how many minutes during this two-hour period was the light off?

The light in a restroom operates with a 15-minute timer that is reset every time the door opens as a person goes in or out of the room. Thus, after someone enters or exits the room, the light remains on for only 15 minutes unless the door opens again and resets the timer for another

The light in a restroom operates with a 15-minute timer that is reset every time the door opens as a person goes in or out of the room. Thus, after someone enters or exits the room, the light remains on for only 15 minutes unless the door opens again and resets the timer for another 15 minutes. If the times listed above are the times at which the door opened from 8:00 to 10:00, approximately how many minutes during this two-hour period was the light off? Read the Full Article »