Alcumus Help

Evaluate $$ \left\lceil\left(-\frac{5}{3}\right)^{2}\right\rceil $$

Ellen baked $$2$$ dozen cupcakes of which half contained chocolate, two-thirds contained raisins, one-fourth contained chocolate chips, and one-sixth contained nuts. What is the largest possible number of cupcakes that had none of these ingredients?

How many base 10 four-digit numbers, $$ N=\underline{a}\,\underline{b}\,\underline{c}\,\underline{d} $$ satisfy all three of the following conditions?
(i)$$ 4,\!000\leq N < 6,\!000 $$
(ii) N is a multiple of 5;
(iii)$$ 3\leq b < c\leq6 $$.

Please do NOT post new problems until we find the time to post an answer/solution.

that is, people give me ans on the chatO_O they didn't post it here

If $$y > 0$$, Find the range of all possible values of y such that $$\lfloor{y}\rfloor*\lceil{y}\rceil=42$$. Express your answer using interval notation.