Is the area of a certain square greater than the area of a certain rectangle?(1) A side of the rectangle equals to a side of the square.
If the longer side (length) of the rectangle is equal to the side of the square, then the area of the square is greater.
If the shorter side (width) of the rectangle is equal to the side of the square, then the area of the rectangle is greater.
Not sufficient.
(2) A side of the rectangle is twice longer than a side of the square.
If the other side of the rectangle is shorter than 1/2 of the side of the square, then the area of the square is greater.
If the other side of the rectangle is longer as well , then the area of the rectangle is greater.
Not sufficient.
(1)+(2) The shorter side (width) of the rectangle is equal to the side of the square and the longer side (length) of the rectangle is twice longer than the side of the square, therefore the area of the rectangle is greater. Sufficient.
Answer: C.
Hope it's clear.