How many positive even integers less than 100 contain digits 4 or 7? Choose the correct choice from the following answers.
A) 16  B) 17  C) 18  D) 19  E) 20
One digit numbers: 4   Two digit numbers:   4 at tens place: 40,42,44,46,48   7 at tens place: 70,72,74,76,78   4 at units place: 14,24,34,54,64,84,94 (duplicates removed)   If 7 is at units place, the number cant be even   Total:1+5+5+7= 
<gadget id="calculator">1+5+5+7</gadget>
<output>18</output>
18   Answer 18
<result>C</result>
How many positive even integers less than 100 contain digits 4 or 7?