Mr. Smith calculated the average of 10three digit numbers. But due to a mistake he reversed the digits of a number and thus his average increased by 9.9. The difference between the unit digit and hundreds digit of that number is :	Choose one
A) a) 4  B) b) 3  C) c) 2  D) d) 1  E) e) 0
Since the average increased by 9.9 and there were a total of 10 numbers, it means the incorrect number was 99 greater than the correct number.   Say, the correct number was abc (where a, b and c are the digits of the 3 digit number)   Then the incorrect number was cba.   100c + 10b + a - (100a + 10b + c) = 99   99c - 99a = 99(c - a) = 99   99 = 99*1= 
<gadget id="calculator">99*1</gadget>
<output>99</output>
99(c - a)   So c - a= 1   Answer (d) 1)
<result>D</result>
Mr. Smith calculated the average of 10three digit numbers. But due to a mistake he reversed the digits of a number and thus his average increased by 9.9. The difference between the unit digit and hundreds digit of that number is :