A copy room uses a two-bin system to manage inventory of paper whereby a number of bundles of paper are placed by the copy machine (call this bin 1) and an additional 12 bundles are placed in storage (call this bin 2).

When the bundles in bin 1 run out, an order is placed with the supplier and the 12 bundles in bin 2 are retrieved and used during the three day leadtime that they wait for the replenishment order from the supplier.

If demand for paper averages 3 bundles per day with a standard deviation of 0.85, what is the probability of having enough bundles while waiting for the replenishment order?