Two fluids, $$A$$ and $$B$$ exchange heat in a counter-current heat exchanger. Fluid $$A$$ enters at $${420^ \circ }C$$ and has a mass flow rate of $$1$$ $$kg/s.$$ Fluid $$B$$ enters at $${20^ \circ }C$$ and also has a mass flow rate of $$1$$ $$kg/s,$$ Effectiveness of heat exchanger is $$75\% $$. Determine the heat transfer rate and exit temperature of fluid $$B.$$ (Specific heat of fluid $$A$$ is $$1$$ $$kJ/kg$$ $$K$$ and that of fluid $$B$$ is $$4$$ $$kJ/kgK$$).

In computing Wilson’s economic lot size for an item, by mistake the demand rate estimate used was $$40\% $$ higher than the tree demand rate. Due to this error in the lot size computation, the total cost of setups plus inventory holding per unit time, would rise above the true optimum by approximately

At a production machine, parts arrive according to a Poisson process at the rate of $$0.35$$ parts per minute. Processing time for parts have exponential distribution with mean of $$2$$ minutes. What is the probability that a random part arrival finds that there are already $$8$$ parts in the system (in machine $$ + $$ in queue)?

Which of the following materials requires the largest shrinkage allowance, while making a pattern for casting?