Help please!!!-Still need help, please help me!

Any value of  y  in the interval  (10, 11)  will make the equation true, for example....

$\lceil{10.1}\rceil\cdot\lfloor{10.1}\rfloor\,=\,11\cdot10\,=\,110$

But also, any value of  y  in the interval  (-11, -10)  will make the equation true, for example...

$\lceil{-10.9}\rceil\cdot\lfloor{-10.9}\rfloor\,=\,-10\cdot-11\,=\,110$

Since the problem says  y < 0 ,  the only values of  y  that work are those in the interval  (-11, -10) .