Several rectangles cover the unit square. Can I find a disjoint set of them whose area is at least $1/4$?

I am interested in the following question:

Let a finite sequence of rectangles in $\mathbb{R}^2$ be given such that

  1. The edges of the rectangles are parallel to the coordinate axes, and

  2. The rectangles cover the unit square, $[0,1]^2$.

Is it possible to find, among these rectangles, a collection of mutually disjoint rectangles whose combined area is at least $1/4$?

As of yet, I'm not sure if a solution exists. My friend and I have spent a while thinking about this and have gotten nowhere.

Any help is greatly appreciated.


The question linked by @AlonAmit in the comments answers exactly this question, and shows that the answer (at least with the constant $1/4$) is no. For a concrete demonstration, start with a $6\times 6$ square broken into thirty-sixths: $$ \begin{matrix} 0&1&2&3&4&5\\ 6&7&8&9&a&b\\ c&d&e&f&g&h\\ i&j&k&l&m&n\\ o&p&q&r&s&t\\ u&v&w&x&y&z \end{matrix} $$ Now cover each corner $2\times2$ by four individual $(1+\varepsilon)\times (1+\varepsilon)$ rectangles, such that the four rectangles in the upper left ($0,1,6,7$) are mutually overlapping, as are those in each of the other corners. And cover the remaining shape in the center (a cross) by eight individual $(3+\varepsilon)\times(1+\varepsilon)$ rectangles ($28e$, $39f$, $cde$, $ijk$, $kqw$, $lrx$, $fgh$, and $lmn$), such that all eight include the center of the square. Any disjoint set of these rectangles includes at most four of the $(1+\varepsilon)\times(1+\varepsilon)$ rectangles and at most one of the $(3+\varepsilon)\times(1+\varepsilon)$ rectangles, and so has total area just over $7/36\approx 19.4\%$ of the full square.