A set consists of 20 numbers, all are even or multiple of 5. If 9 numbers are even and 12 numbers are multiple of 5, how many numbers is multiple of 10? Choose the correct choice from the following answers: A) 0 B) 1 C) 2 D) 3 E) 5
{Total} = {Even} + {Multiple of 5} - {Both} + {Nether}.   Since{Neither}=0(allare even or multiple of 5) then:   20 = 9 + 12 - {Both} + 0;   {Both}=1(so 1 number is both even AND multiple of 5, so it must be a multiple of 10).   Answer: 1.
<result>B</result>
A set consists of 20 numbers, all are even or multiple of 5. If 9 numbers are even and 12 numbers are multiple of 5, how many numbers is multiple of 10?