<em>Greetings from Brasil...</em>
Observing the line of the problem we can see that each division represents -1/3. From zero to - 1 we have 3 divisions, then - 1/3 for each division.
From scratch, P is the fifth division, so
P = (- 1/3) x 5
<h3>P = - 5/3</h3>
or
<h3>P = - 1.6666...</h3>
<em>just looking at the figure already conclude that P < - 1 and P > - 2</em>
<em>so </em><em>{P | - 2 < P < - 1}</em>
<em>or just P < - 1</em>