Hi manik11,
This question can be solved with a bit of logic and understanding the type of information that you would NEED to know to answer the given question. Based on the information in the prompt, we know that a box has a square base and that 200 identical cylinders could fit in the box (if the cylinders were touching the edges of the box). We're asked for the VOLUME of the box. By definition, we'll need actual numbers for the base and the height of the box, to answer this question.
(1) The radius of each cylinder is 5 centimeters.
This tells us nothing about the height of the cylinders, the base of the box nor the height of the box. Changing the height of the cylinders and/or the base or height of the box will change the volume of the box.
Fact 1 is INSUFFICIENT
(2) The height of the box is 80 centimeters.
This tells us nothing about the base of the box nor anything about the dimensions of the cylinders. Different-sized cylinders and/or a different-sized base will change the volume of the box.
Fact 2 is INSUFFICIENT
Combined, we don't know the height of the cylinders nor the base of the box. Changing those variables will change the volume of the box.
Combined, INSUFFICIENT.
Final Answer: E
GMAT assassins aren't born, they're made,
Rich