One of the open problems in Algebraic topology is the Peterson hit problem for the algebra polynomial $P_t = \mathbb Z_2[x_1, \ldots, x_t] = H^{*}(B\mathbb Z_2^{t}, \mathbb Z_2)$ of $t$ generators $x_1, \ldots, x_t$ with $|x_j| = 1.$ The problem seeks a minimal set of the $\mathbb Z_2$-graded vector space $\{(\mathbb Z_2\otimes_{\mathcal A_2} P_t)_n\}_{n\geq 0}.$ It has been thoroughly studied for 35 years in a variety of contexts by many authors and completely solved for $t\leq 4.$ In the case $t = 5$ and some "generic" degrees, the problem was studied by many authors. In this article, we explicitly solve the hit problem of five variables in the generic degree $5(2^{s}-1) + 42.2^{s}$ for any $s\geq 0.$ The result confirms Sum's conjecture \cite{N.S2} on the relation between the minimal set of $\mathcal A_2$-generators for the algebras $P_{t-1}$ and $P_{t}$ in the case $t=5$ and the above generic degree. An efficient approach to surveying the hit problem in this case has been presented. As an application, we obtain the dimension of $(\mathbb Z_2\otimes_{\mathcal A_2} P_t)_n$ for $t = 6$ and the generic degree $n = 5(2^{s+5}-1) + 42.2^{s+5}$ for all $s\geq 0.$ At the same time, we show that the fifth Singer algebraic transfer is an isomorphism in bidegree $(5, 47.2^{s})$ for any $s\geq 0.$