Answer:
0.05
Explanation:
The Sample Space is that of numbers between 1-80 (both end numbers inclusive).
Therefore: number of elements in the Sample space, n(S)=80
Multiples of 20 are: 20,40,60 and 80
n(Multiples of 20) =4
The probability of obtaining a multiple of 20 when the button is pressed one time is:
P(Multiple of 20)