How many positive integers less than 25 are prime numbers, odd multiples of 5, or the sum of a positive multiple of 2 and a positive multiple of 4? Choose the correct answer:
A) 27 B) 25 C) 24 D) 22 E) 20
9 prime numbers less than 28: {2, 3, 5, 7, 11, 13, 17, 19, 23}   2 odd multiples of 5: {5, 15}   10 numbers which are the sum of a positive multiple of 2 and a positive multiple of 4: {6, 8, 10, 12, 14, 16, 18, 20, 22, 24}   Notice, that 5 is in two sets, thus total # of integers satisfying the given conditions is  9+2+10-1= 
<gadget id="calculator"> 9+2+10-1</gadget>
<output>20</output>
20.   Answer: 20.
<result>E</result>
How many positive integers less than 25 are prime numbers, odd multiples of 5, or the sum of a positive multiple of 2 and a positive multiple of 4?