If $A$ and $B$ are two sets,then $(A - B) \cup (B - A) \cup (A \cap B)$ is equal to

$A$ ball is dropped from a height of $20 \ m$ above the surface of water in a lake. The refractive index of water is $4/3$. $A$ fish inside the lake, in the line of fall of the ball, is looking at the ball. At an instant, when the ball is $12.8 \ m$ above the water surface, the fish sees the speed of the ball as ........ $m/s$ $[g = 10 \ m/s^2.]$

Compared to blood,our lymph has:

When $X$ amperes of current is passed through molten $AlCl_3$ for $96.5 \ s$,$0.09 \ g$ of aluminium is deposited. What is the value of $X$?

Which of the following aquatic ferns is used as an excellent biofertilizer?

Which of the following metals belong to the same group in the periodic table?