What is the respective number of $\alpha $ and $\beta $ particles emitted in the following radioactive decay

$_{90}{X^{200}}{ \to _{80}}{Y^{168}}$

Consider the following radioactive decay process 

${ }_{84}^{218} A \stackrel{\alpha}{\longrightarrow} A_1 \stackrel{\beta^{-}}{\longrightarrow} A_2 \stackrel{\gamma}{\longrightarrow} A_3 \stackrel{\alpha}{\longrightarrow} A_4 \stackrel{B^{+}}{\longrightarrow} A_5 \stackrel{\gamma}{\longrightarrow} A_6$

The mass number and the atomic number $A _6$ are given by 

Neutrino is a particle, which is

In the given reaction $_z{X^A}{ \to _{z + 1}}{Y^A}{ \to _{z - 1}}{K^{A - 4}}{ \to _{z - 1}}{K^{A - 4}}$ Radioactive radiations are emitted in the sequence

In the disintegration series

$_{92}^{238}U\xrightarrow{\alpha }x\xrightarrow{\beta }_Z^AY$

The value of $Z$ and $A$ respectively will be

Which of the following processes represents a gamma-decay