If the average (arithmetic mean) of a and b is 110, and the average of b and c is 150, what is the value of a − c?  Select: A) −220 B) −100 C) 100 D) −80 E) It cannot be determined from the information given
Question: a - c = ?   (a + b)/ 2 =110 ===&gt; a + b = 220   (b + c)/2 = 150 ===&gt; b + c = 300   (a + b) - (b + c) = 220 - 300 ===&gt; a + b - b - c = - 80 ===&gt; a - c = - 80   Answer: −80
<result>D</result>
If the average (arithmetic mean) of a and b is 110, and the average of b and c is 150, what is the value of a − c?