If the average (arithmetic mean) of a and b is 40 and the average of b and c is 60, what is the value of c − a?  Options
A) 25  B) 40  C) 90  D) 140  E) It cannot be determined from the information given.
-(a + b = 80)   b + c=120   c-a=40   B. 40
<result>B</result>
If the average (arithmetic mean) of a and b is 40 and the average of b and c is 60, what is the value of c − a?