Probability is expressed as
number of favorable outcomes/number of total outcomes
The total number of outcomes from 1 to 80 = 80
The multiples of 12 between 1 and 80 are
12, 24, 36, 48, 60, 72
The number of multiples of 12 = 6
number of favorable outcomes(numbers that are not multiples of 12) = 80 - 6 = 74
the probability that the spinner will land on a number that is not a multiple of 12
= 74/80
= 37/40