1. if five coins are flipped, what is the probability that
all five coins land on tails?
Suppose the five coins are pennies with dates 2012, 2013,
2014, 2015, and 2016.
1/2 of the time the 2012 penny will land on tails.
1/2 of those times, or 1/4 of the time, the 2013 penny will
also land on tails.
1/2 of those times, or 1/8 of the time, the 2014 penny will
also land on tails.
1/2 of those times, or 1/16 of the time, the 2015 penny will
also land on tails.
1/2 of those times, or 1/32 of the time, the 2016 penny will
also land on tails.
Answer: 1/32 of the time, or a probability of 1/32.
That's about 3% of the time.
-------------------------------
2.a field goal kicker makes 3 of every 7 attempts at a
field goal. if he kicks 3 field goals in a certain game,
what is the probability that he'll make all three?
3/7 of the time he'll make the first field goal
3/7 of those times, or 9/49 of the time, he'll also
make the second field goal.
3/7 of those times, or 27/343 of the time, he'll also
make the third field goal.
Answer: 27/343 of the time, or a probability of 27/343.
That's about 8% of the time.
Edwin
