Baking soda is used to remove permanent hardness of water.

Statement-1: Permutit process is more efficient than synthetic resin method.

Statement-2: In the synthetic resin method, soluble salt of sodium is formed.

Complete the given equation.

${\mathrm{MgSO}}_4+{\mathrm{Na}}_2{\mathrm{SO}}_4\to$

Complete the given equation.

${\mathrm{CaSO}}_4+{\mathrm{Na}}_2{\mathrm{CO}}_3\to$

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$