For the same inlet and outlet temperatures of hot and cold fluids, the Log mean temperature Difference $$(LMTD)$$ is

An item can be purchased for Rs.$$100.$$ The ordering cost is Rs.$$200$$ and the inventory carrying cost is $$10\% $$ of the item cost per annum. If the annual demand is 4000 units, the economic order quantity (in units) is

A project consists of three parallel paths with mean durations and variances of $$(10,4), (12,4)$$ and $$(12,9)$$ respectively. According to the standard $$PERT$$ assumptions, the distribution of the project duration is

The precedence relations and durations of jobs in a project are given below:
(a) Draw the activity-on-arc project network
(b) Determine all critical path(s) and their duration(s).
(c) What is the total float for jobs $$B$$ and $$D?$$