math
posted by Mackenzie .
your social security number is a 9 digit number. suppose that the last 4 digits are chosen randomly from the number 09.
a. how many sequences are possible for the last 4 digits?
b. what is the probability of getting 5 or 0 in the last digit.
c. what is the probability of getting two 5's in the last two digits?

math 
drwls
a.) 0000 through 9999 = 10,000 possibilities
b.) 1/10 + 1/10 = 1/5
c.) 1 (55) out of 100 (00 through 99) 
math 
Mackenzie
for a i thought you were supposed to do 9*8*7*6 and the answer that i got was 3,024.
for b i got 9*8=72
for c i got 9*9=81
does that make sense 
math 
PsyDAG
The numerals get smaller if you are considering probabilities without replacement. In other words, using a numeral in one position would prohibit its use in other positions. However, the use of any numeral does not effect the probabilities of the remaining numerals.
I hope this helps a little more. Thanks for asking.
Respond to this Question
Similar Questions

math ALGEBRA
When the digits of twodigits numbers are reversed, the new number is 9 more than the original number, and the sum of the digits of the original number is 11. What is the original number. Can some one please help me here? 
Math
A social security number consists of nine digits. How many different social security numbers are possible if repetition of digits is permitted? 
Math
Social Security Numbers A social security number consists of nine digits. How many different social security numbers are possible if repetition of digits is permitted? 
math
What mystery number has 8 digits; none of the digits are the same. It is evenly divisible by 10. The value of one of the digits is 80,000. The digits in the millions place is the largest 1digit odd number. The digit in the thousands … 
Math
1.) A security code has seven characters. Each code begins with two digits, then two letters, and finally three digits. the number of distinct security codes possible if repetition is allowed? 
mathprobability
A state lottery has a daily drawing to form a fourdigit number. The digits 1 through 9 are randomly selected for each of the four digits. For each selection any one of the digits 1 through 9 are possible. What is the probability to … 
College Mathematics
Counting Principles and Permutation. A social security number consists of 9 digits. How many different social security numbers are possible if repetition of digits is permitted 
College Mathematics
Counting principles and permutations. A social security number consists of 9 digits. How many different social security numbers are possible if repetition of digits is permitted. digits 09 
Math Nunbers
The sum of the digits of a positive three digit number Is 19. The tens digits is four less than twice the hundreds digit. The number is decreased by 99 when the digits are reversed. Find the number 
Algebra
A number consist of 3 digits.The middle digit is 0 and the sum of the first and last digits is 13.If the digits are reversed the number is increased by 297.Find the original number.MY SOLUTION: let x=the 1st digit & y=last digit x+y=13 …