Expert: Bobby Soltani - 6/19/2009

Question
1)From a group of 125 boys and 150 girls, what are the odds of randomly selecting a girl?
2)Determine the probability of each event (A person was born on a weekday)
3) Find the probability of each outcome if a computer randomly  chooses a letter in the word “mathematical.”
the letter a or c

please help me with explanation

Thanks

sree

Answer
Hi,

The probability of an event is equal to the number of favorable outcomes divided by the number of possible outcomes.

1)
Number of favorable outcomes (selecting a girl) is 150.
Number of possible outcomes is 150 + 125, or 275.
Therefore, the probability is:
P(selecting a girl) = 150/275 = 0.55, or 55%

2)
Favorable outcomes is 5 weekdays
Possible outcomes is 7 days in a week.

3)
Favorable outcomes is 3 (number of a's) + 1 (number or c's) which equals 4.
Possibile outcomes is 12, the number of letters in the word mathematical.

Let me know if you have any questions.

Bobby