$1$ point

Algorithm A takes $5n^2$ steps of work to complete a task of size $n.$ Thus for a task of size $4,$ it takes $542$ or $80$ steps of work.

Algorithm B takes ${1\mathrm{.}5}^n$ steps of work to complete a task of size $n.$ Thus it would take $1\mathrm{.}54$ or $5\mathrm{.}0625$ units of work to solve a problem of size of $4.$

Which algorithm is non$-$polynomial?

Why is the polynomial algorithm considered more doable than the non$-$polynomial one?