The average (arithmetic mean) of 4 positive integers is 30. If the average of 2 of these integers is 15, what is the greatest possible value that one of the other 2 integers can have?
Select.
A) 55 B) 89 C) 100 D) 109 E) 115

Rationale: "a + b + c + d = 120 a + b = 30 c + d = 90 greatest possible = 89 ( just less than 1 ) answer = b"
Answer: B