Arrivals at a telephone booth are considered to be Poisson, with an average time of $$10$$ minutes between successive arrivals. The length of a phone call is distributed exponentially with mean $$3$$ minutes. The probability that an arrival does not have to wait before service is

A regression model is used to express a variable $$Y$$ as a function of another variable $$X.$$ this implies that

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

The supply at three sources is $$50, 40$$ and $$60$$ units respectively whilst the demand at the four destinations is $$20, 30, 10$$ and $$50$$ units. In solving this transportation problem