For the $A.P.$ formed by positive multiples of $4$,$d = \ldots \ldots \ldots \ldots .$

$2, \frac{5}{2}, 3, \frac{7}{2}, \ldots$ are $APs$? If they form an $AP$,find the common difference $d$ and write three more terms.

The digits of a three-digit number form an $A.P.$ and their sum is $15$. The number obtained by reversing the order of the digits exceeds the original number by $594$. Find the original number.

For the $A.P.$ $-2, -4, -6, \ldots,$ the common difference $d = \ldots$

The list of numbers $-10, -6, -2, 2, \ldots$ is

Write the first three terms of the $APs$ when $a$ and $d$ are as given below:
$a = \sqrt{2}, d = \frac{1}{\sqrt{2}}$