Which of these is not a method used to calculate financial charges

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?

Jonathan puts $400 in a bank account. each year the account earns 6% simple interest. how much interest will be earned in 5 years?

If the probability of an event happening is 65% then the probability this event does not occur?