Mahadevan was puzzled by the strange way in which his grand daughter was counting. She began to count on the fingers of her left hand. She started by calling the thumb 1, the first finger 2, middle finger 3, ring finger 4, little finger 5, then she reversed direction, calling the ring finger 6, middle finger 7, first finger 8, thumb 9, then back to the first finger for 10, middle finger for 11, and so on. She continued to count back and forth in this peculiar manner until she reached a count of 20 on her ring finger.
Seeing this, Mahadevan told her "If you can find on which finger you will count 2017, I will buy you an ice cream". Can you find on which finger she will count 2017? Explain the steps you used to arrive at the answer.
