A grain silo contains 180 tons of corn at the beginning of a work day. During the day, corn is removed at the constant rate of 12 tons per hr, so that the weight of corn in the silo t hours after the beginning of the work day is w=F(t) tons, where F(t)= 180-12t. Find F^-1(120) and explain what it represents in terms of weight and time.
F(t) = 180 - 2t after t hours there are F(t) tons of corn we could make a table like this ton hrs 180 0 168 1 156 2 ... look for 120 in the left column and how many hrs it took to have 120 tons it's much simpler to solve for t 120 = 180 - 12t 12t = 60 t = 5 5 = F^(-1)(120) is the number of hours required to have 120 tons of corn in the silo
