# coins

1. ### coins and weight....with possible error in balance measure

I have run thru this problem: We are given 1000 coins, each of which weights a natural number of grams , and a two-pan balance, measuring in grams the weight difference between the objects placed on two plates. The balance is generally reliable, but for a construction defect we know that at...
2. ### An investigation of piles of coins

Hi all, this is my first post so apologies if this is in the wrong thread! I am well and truly stuck with this investigation and any help would be greatly appreciated. The question is: Start with two unequal piles of coins. Shift enough coins from the larger pile to the smaller pile, so that...
3. ### Probability of Coins Flips

When I initially thought about the problem, I thought of it as if both had 4 coins, then they would on average get the same number of heads. If Person A had one more coin, then it would be a 50/50 shot for Person A to have more each time. But the more I think about this, its making less sense to...
4. ### Growth rate and regular coins, and one unfair coin.

I'm completely lost on this one; I haven't encountered a question like this before (with two growth rates). So, there's this experimenter who tosses 4 coins (this is toss 1) and about half of them (2) land with heads up. She adds the amount that landed heads up (2) to the intial number of...

16. ### I need help with my Probability Course assignment

I have got a few questions for my assignment. I can't seem to solve 9 of these. I have no other way of getting help for these. I know these will come up for my exams. Please help me solve them.(Worried) 1. Suppose S is uncountable. Show that it is impossible that P({s}) > 0 for every s that...
17. ### Balancing Coins

You have 22 coins which all weigh the same and 2 coins that are heavier than the rest, but equal in weight to each other. You have a balance that can compare two groups of coins. What is the smallest number of weighings necessary to find the two heavy coins?
18. ### Coins in a jar word problem

I just joined today, thank you for making this forum. I will be coming here often, again thank you all so much. Here is the problem. The problem starts with coins in a jar and I must come up with the number of coins of each denomination. The number of quarters is unknown, number of dimes...
19. ### Coins Probability

You have some coins in your pocket: 3 quarters, 2 dimes, and 4 pennies. What’s the probability that 3 coins taken randomly will be worth more than 50 cents?
20. ### tossing the two coins together, until for the first time either two heads appear ....

Tom and Bob play a game by each tossing a fair coin. The game consists of tossing the two coins together, until for the first time either two heads appear when Tom wins, or two tails appear when Bob wins. 1) Show that the probability that Tom wins are or before the nth toss is \frac{1}{2} -...