How many heads before you will be impress?

Question

"I have developed the power of mind over matter. If one of you will stand in one corner of this room and toss 100 pennies, I will stand in the opposite corner and, through the sheer power of thought, cause those penny tosses to come up heads. Now mind you, I don't claim that each and every toss will come up heads—I haven't yet perfected this skill to the level of 100 percent. But what I will do is produce an impressive number of heads, to the point where you will at least be willing to take my claim seriously."

Answer 1

I think if you can score 70 heads in 100 throws that you would definitely have my attention. The odds of doing that by chance are 1 in 25,477.

But I get to choose the coin.

Answer 2

All combinations are possible. It is possible to get 100 heads when throwing 100 coins. Even though theoretical probability tells us we will get 50 heads, that is based on what happens in the long run. It is much more likely that there will be a different number of heads when throwing 100 coins.

One trial would not be enough to convince me. I would be impressed if 80 or more heads came up in 25 consecutive trials. These are enough samples to indicate if the experimental probability is not 50% with these coins. Now, why the probability is not 50% should be researched. The coins could be weighted or the claim could be true. Each possibility needs to be tested.

Answer 3

Actually one side of the penny is heavier than the other causing a disproportionate number of heads tosses.

Answer 4

Bollocks

Answer 5

I could not understand what you said... but I am sure what you are saying is based on probability.

Answer 6

OK, I'll buy that. Not really, but I thought that would be a nice thing to say.

Answer 7

we can do it using probability..