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.

Working simultaneously at their respective constant rates, Machines A and B produce 800 nails in x hours. Working alone at its constant rate, Machine A produces 800 nails in y hours. In terms of x and y, how many hours does it take Machine B, working alone at its constant rate, to produce 800 nails?

Working simultaneously at their respective constant rates, Machines A and B produce 800 nails in x hours. Working alone at its constant rate, Machine A produces 800 nails in y hours. In terms of x and y, how many hours does it take Machine B, working alone at its constant rate, to produce 800 nails? A. x/(x+y) B. y/(x+y) C. xy/(z+y) D. xy/(x-y) E. zy/(y-x) Correct Answer: E Full […]

Working simultaneously at their respective constant rates, Machines A and B produce 800 nails in x hours. Working alone at its constant rate, Machine A produces 800 nails in y hours. In terms of x and y, how many hours does it take Machine B, working alone at its constant rate, to produce 800 nails? Read the Full Article »

Three-fourths of the area of a rectangular lawn 30 feet wide by 40 feet long is to be enclosed by a rectangular fence. If the enclosure has full width and reduced length rather than full length and reduced width, how much less fence will be needed?

Three-fourths of the area of a rectangular lawn 30 feet wide by 40 feet long is to be enclosed by a rectangular fence. If the enclosure has full width and reduced length rather than full length and reduced width, how much less fence will be needed? A. 2(1/2) B. 5 C. 10 D. 15 E.

Three-fourths of the area of a rectangular lawn 30 feet wide by 40 feet long is to be enclosed by a rectangular fence. If the enclosure has full width and reduced length rather than full length and reduced width, how much less fence will be needed? Read the Full Article »

Tanks A and B are each in the shape of a right circular cylinder. The interior of Tank A has a height of 10 meters and a circumference of 8 meters, and the interior of Tank B has a height of 8 meters and a circumference of 10 meters. The capacity of Tank A is what percent of the capacity of Tank B?

Tanks A and B are each in the shape of a right circular cylinder. The interior of Tank A has a height of 10 meters and a circumference of 8 meters, and the interior of Tank B has a height of 8 meters and a circumference of 10 meters. The capacity of Tank A is

Tanks A and B are each in the shape of a right circular cylinder. The interior of Tank A has a height of 10 meters and a circumference of 8 meters, and the interior of Tank B has a height of 8 meters and a circumference of 10 meters. The capacity of Tank A is what percent of the capacity of Tank B? Read the Full Article »

If rectangle ABCD is inscribed in the circle above, what is the area of the circular region?

If rectangle ABCD is inscribed in the circle above, what is the area of the circular region? A. 36.00 π B. 42.25 π C. 64.00 π D. 84.50 π E. 169.00 π Correct Answer: B Full explanation coming soon. Send us a note if you’d like this added to the express queue! You’ll find tons of practice

If rectangle ABCD is inscribed in the circle above, what is the area of the circular region? Read the Full Article »

In the xy plane, the distance between the origin and the point (4,5) is the same as the distance between which of the following two points?

In the xy plane, the distance between the origin and the point (4,5) is the same as the distance between which of the following two points? A. (-3,2) and (-7,8) B. (-2,1) and (3,5) C. (-2,-4) and (1,0) D. (3,2) and (8,7) E. (4,1) and (-1,-4) Correct Answer: B Full explanation coming soon. Send us a note

In the xy plane, the distance between the origin and the point (4,5) is the same as the distance between which of the following two points? Read the Full Article »