Question 1086790
Question:
From 20 tickets marked with the first 20 numerals, one is drawn at random. what is the probability that it will be a multiple of 3 or 7.
 
Solution:
It is assumed that it is equally probability to draw any of the 20 tickets.
then
P(3)=1/20
P(7)=1/20
P(3 or 7)=1/20+1/20=2/20=1/10