Please solve for B$.$

Consider a reversible heat engine that employs a hot reservoir at a temperature of $850$ K and a cold reservoir at $250$ K $.$

$($a$)$ What is the entropy change of the hot reservoir during a period in which $5010$ J is extracted from the hot reservoir?

$-5\mathrm{.}891/$K

$($b$)$ What is the change in the entropy of the cold reservoir?

$0$J$//$K

$($c$)$ Find the change in the entropy of the engine itself during this time.

$0\mathrm{.}0000$