If the average (arithmetic mean) of a and b is 45 and the average of b and c is 70, what is the value of c − a?
Options: A) 25 B) 50 C) 90 D) 140 E) It cannot be determined from the information given.
the arithmetic mean of a and b =(a+b)/2=45 -- a+b=90 --1   similarly for b+c=140 --2   subtracting 1 from 2 we have   c-a=50 ANSWIt cannot be determined from the information given.R:It cannot be determined from the information given.
<result>E</result>
If the average (arithmetic mean) of a and b is 45 and the average of b and c is 70, what is the value of c − a?