If the average (arithmetic mean) of a and b is 45 and the average of b and c is 90, what is the value of c âˆ’ a?	Choose the most appropriate option
A) 25  B) 90  C) 100  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=180 --2   subtracting 1 from 2 we have   c-a=90;   ANSWER:90
<result>B</result>
If the average (arithmetic mean) of a and b is 45 and the average of b and c is 90, what is the value of c âˆ’ a?