I used the =RAND formula to find the r1 of random numbers. Which is also depicted in column r2. Then I used formula that was used to obtain the time between breakdowns is (6x sqrt x r1). This information is depicted in the column labeled Time between Breakdowns. To find the repair time for the copier used the VLOOKUP formula. The formula looks at r2 RAND number and the P(x) and Cumulative number (=VLOOKUP(E20,Lookup,2). This gives me the number of days that it would take to repair the copier. Now that we know the number of days that it will take to repair the copier, we can calculate the average time it would take per week. We do this by using the =Average(), so the average breakdown per week is 3.99 Now for each repair there is at least one day and a maximum of 4 days when the business is closed and loosing copies. For day one we calculate a number of copies lost based on the information we have that the shop usually makes between 2000 and 8000 copies, so number of copies is 2000+rand()*6000. For the second, third, and fourth days we check the number of days spent on the repair in that period and calculate losses (copies) if the repair was longer than one, two, or three days respectively. Once we know the number of copies lost per day we calculate monetary loss by multiplying number of copies by $0.1. Losses from all periods are added and logical test is performed, if the total losses are less than $12000 the second copier is not needed, otherwise the second copier is