The math professor wrote an equation f(x) = x and outlined t as variety of options at f(x) = 5 and u as variety of options at f(x) = 3. He additional defines N as N = t+u

Two programmers determined to edit mathematical equations in a pc belonging to math professor. The first programmer designed a software program that takes absolutely the worth of the operate each 2 minute ranging from 1st minute, the second programmer designed one other program that subtracted 5 from the ensuing equation each 2 minutes, ranging from 2nd minute. For occasion, a operate f(x) = 3x-4 will appear like, abs(abs(3x-4) – 5) after 3 minutes.

Professor left the pc open for a while, and returns again to test the worth of N, he finds the worth of N elevated by 84 after which decreased by 84 in 3 consecutive minutes. After what number of minutes did he return?