The bank will perform the calculations i = Prt and B = P + i every month because the interest is compounded monthly.
The formula i = Prt is used to calculate the interest earned in a given month, and B = P + i is used to update the account balance after each month's interest is added.
There are 12 months in a year, and the money is left in the account for 5 years, so the total number of times these calculations will be performed is:
12 months/year * 5 years = 60 times
So, the bank will perform these calculations 60 times over the 5-year period. The correct answer is "60 times."