During open-heart surgery, a patient’s blood is cooled down to 25 °C from 37 °C using a concentric tube counter-flow heat exchanger. Water enters the heat exchanger at 4 °C and leaves at 18 °C. Blood flow rate during the surgery is 5 L/minute.

Use the following fluid properties :

$$ \begin{array}{|c|c|c|} \hline \text { Fluid } & \text { Density }\left(\mathrm{kg} / \mathrm{m}^3\right) & \text { Specific heat }(\mathrm{J} / \mathrm{kg}-\mathrm{K}) \\ \hline \text { Blood } & 1050 & 3740 \\ \hline \text { Water } & 1000 & 4200 \\ \hline \end{array} $$

Effectiveness of the heat exchanger is _________ (round off to 2 decimal places).

In a linear programming problem, if a resource is not fully utilized, the shadow price of that resource is

Which one of the following is NOT a form of inventory?

Activities A to K are required to complete a project. The time estimates and the immediate predecessors of these activities are given in the table. If the project is to be completed in the minimum possible time, the latest finish time for the activity G is ______ hours.

$$ \begin{array}{|c|c|c|} \hline \text { Activity } & \text { Time (hours) } & \text { Immediate predecessors } \\ \hline \text { A } & 2 & - \\ \hline \text { B } & 3 & - \\ \hline \text { C } & 2 & - \\ \hline \text { D } & 4 & \text { A } \\ \hline \text { E } & 5 & \text { B } \\ \hline \text { F } & 4 & \text { B } \\ \hline \text { G } & 3 & \text { C } \\ \hline \text { H } & 10 & \text { D, E } \\ \hline \text { I } & 5 & \text { F } \\ \hline \text { J } & 8 & \text { G } \\ \hline \text { K } & 3 & \text { H, I, J } \\ \hline \end{array} $$