Please i need manual solution pleasssse

For the data in Table $2\mathrm{.}9,$ evaluate the cost of the plan given in the table if an in$-$house regular hour is $10$$$,$ overtime hour is $15$$$,$ and a contract man$-$hour costs $25.$ In addition, every backlog man$-$hour delayed from period t to t $+1$ costs $5.$ Develop an alternative competitive plan in which you can have instead of $5$ skilled employees have a mixture of skill and unskilled. The hour of unskilled worker is $8$$$.$