II.14 Piled up two-face coins

There are some two-faced coins and piles up every coin of which heads face upward initially.

Answer the following questions.

(1) In case there are three coins, as the 1st operation, flip one piece of the top of coins.

As the 2nd operation, flip piled two pieces from the top of coins.

As the 3rd operation, flip piled three pieces all. As the 4th operation, flip one piece of the top again.

After this, continue the same cycle of operation of flipping two pieces from the top, three pieces all, and one piece of the top-------.


(1)-1 Find the number of times of operation in case heads of all coin face upward for the first time.

(1)-2 When you perform operation 100 times, find the number of pieces of the coin of which heads face upward.

(2) In case there are two coins, as the 1st operation, flip one upper piece.

As the 2nd operation, flip plied two all.

As the 3rd operation, flip one upper piece again.

After this, continue the same cycle of operation of flipping two all, one upper piece, two all,----------.

When you perform operation 100 times, which face of heads and/or tails of two coins face upwards respectively?











Answer
(1)-1 9 times
(1)-2 2 pieces
(2) Both tails of two coins face upward.