Which of the following solutions will have $pH$ close to $1.0$?

Following solutions were prepared by mixing different volumes of $NaOH$ and $HCl$ of different concentrations:
$a. \; 60 \; mL \; \frac{M}{10} \; HCl + 40 \; mL \; \frac{M}{10} \; NaOH$
$b. \; 55 \; mL \; \frac{M}{10} \; HCl + 45 \; mL \; \frac{M}{10} \; NaOH$
$c. \; 75 \; mL \; \frac{M}{5} \; HCl + 25 \; mL \; \frac{M}{5} \; NaOH$
$d. \; 100 \; mL \; \frac{M}{10} \; HCl + 100 \; mL \; \frac{M}{10} \; NaOH$
$pH$ of which one of them will be equal to $1$?

Which of the following solutions has the highest $pH = 14$?

Weight of $Ca(OH)_2$ needed to prepare $250 \ mL$ of solution with $pH = 13$. (in $g$)

If the $pH$ of a solution of an alkali metal hydroxide is $13.6$,the concentration of hydroxide is

$75 \ mL$ of $0.2 \ M \ HCl$ is mixed with $25 \ mL$ of $1 \ M \ HCl$. To this solution,$300 \ mL$ of distilled water is added. What is the $pH$ of the resultant solution?