Answer :
The number of multiples of 5 from 1 to 100 is:
1≤5n≤100
1/5≤n≤20, since n must be an integer
1≤n≤20
So the multiples of five number 20-1+1=20 elements, and the probability of choosing one of the multiples from the first 100 positive integers is:
P(5n)=20/100=1/5
1≤5n≤100
1/5≤n≤20, since n must be an integer
1≤n≤20
So the multiples of five number 20-1+1=20 elements, and the probability of choosing one of the multiples from the first 100 positive integers is:
P(5n)=20/100=1/5