Even numbers always end with a digit of 0, 2, 4, 6 or 8. The set of even numbers between 1 and 20 are 2,4,6,8,10,12,14,16,18.The numbers which are multiples of 3 and lie between 1 and 20 are 3,6,9,12,15,18.
Total numbers which are even and multiple of 3 between 1 and 20 are 2,3,4,6,8,9,10,12,14,15,16,18. There are 13 numbers in all.
There are 20 numbers between 1 and 20.
Probability of picking an even number number or a multiply of three = [tex] \frac{13}{20} [/tex]
