How many positive even integers less than 100 contain digits 5 or 9? Choose the correct choice from the following choices
A) 16  B) 10  C) 18  D) 19  E) 20

Rationale: two digit numbers : 5 at tens place : 50 , 52,54 , 56,58 9 at tens place : 90 , 92,94 , 96,98 if 5 and 9 is at units place , the number cant be even total : 5 + 5 = 10 answer b
Answer: B