Write the number of terms in the expansion of

In the binomial expansion of $(a+b)^{n}$, total number of terms will be $(n+1)$.

Now, $\left[\left(2 x+y^{3}\right)^{4}\right]^{7}=\left(2 x+y^{3}\right)^{28}$

Therefore, in the expansion of $\left[\left(2 x+y^{3}\right)^{4}\right]^{7}$, total number of terms will be $28+1=29$.