First Round

Francisca has a square piece of paper whose sides have length $10$ cm. She also has a rectangular piece of paper having the exact same area as the square piece of paper. She puts the rectangle right on top of the square, putting the left bottom corner of both pieces of paper in the same spot. Exactly one quarter of the square remains uncovered by the rectangle. What is the length in centimetres of the long side of the rectangle?



A) $12$

B) $12\frac{1}{4}$

C) $12\frac{1}{2}$

D) $12\frac{3}{4}$

E) $13\frac{1}{3}$