Question Number 1397 by 314159 last updated on 28/Jul/15
$${Arrange}\:\mathrm{8}\:{coins}\:{in}\:{one}\:{line}\:{on}\:{a}\:{table} \\ $$$${such}\:{that}\:{the}\:{head}\:{or}\:{tail}\:{will}\:{be}\:{facing} \\ $$$${upward}.{Try}\:{to}\:{flip}\:{two}\:{neighboring}\:{coins}\: \\ $$$${that}\:{are}\:{not}\:{with}\:{identical}\:{face}\:{upside}\:{down}.{After}\: \\ $$$${several}\:{operations}\:,\:{how}\:{many}\:{different}\: \\ $$$${ways}\:{can}\:{the}\:{heads}\:{and}\:{tails}\:{be}\:{arranged} \\ $$$${in}\:{one}\:{line}\:{on}\:{the}\:{table}. \\ $$
Commented by prakash jain last updated on 28/Jul/15
$$\mathrm{Initial}\:\mathrm{arragment}: \\ $$$$\mathrm{HHHHHHHH} \\ $$$$\mathrm{or} \\ $$$$\mathrm{HTHTHTHT} \\ $$
Commented by 314159 last updated on 30/Jul/15
$${pls}..{consider}\:{as}\:{u}\:{think}... \\ $$$${I}\:{also}\:{don}'{t}\:{know}\:{the}\:{solution}\:{of}\:{that}\:{problem}. \\ $$