If the average (arithmetic mean) of a and b is 215, and the average of b and c is 160, what is the value of a − c? Choose the correct choice from the following options
A) −220 B) −100 C) 100 D) 110 E) It cannot be determined from the information given
Question: a - c = ?   (a + b)/ 2 =215 ===&gt; a + b = 430   (b + c)/2 = 160 ===&gt; b + c = 320   (a + b) - (b + c) =430- 320 ===&gt; a + b - b - c = 110 ===&gt; a - c = 110   Answer: 110
<result>D</result>
If the average (arithmetic mean) of a and b is 215, and the average of b and c is 160, what is the value of a − c?