Last Question:
Your friend George gives you the following argument about coin tossing:
The odds of three tossed coins turning up all heads or all tails is one in two, that is 50-50. That is because anytime you toss three coins, at least two must match, either two heads or two tails. So that means the third coin – which is equally likely to be heads or trails, determines the odds.”
Is your friend George right? If not, what are the odds of three tossed coins turning up all heads or all tails?
Answer:
I am afraid George is dead wrong. The odds for each coin are independent of the others. There are two possible outcomes for a singe coin. I found possible outcomes for two coins and eight possible outcomes for three coins:
Coin 1 Coin 2 Coin 3
H H H
H H T
H T H
H T T
T H H
T H T
T T H
T T T
In only two tosses out of eight will the coins land all heads or all tails.
Today’s Question:
There are 22 gloves in a drawer: Five pairs of red gloves, four pairs of yellow gloves and two pairs of green gloves. If the lights are out and you must select the gloves in the dark, how many must you choose to ensure that you have at least one matching pair?