# Math

a number between 1000 and 9999, inclusive, is chosen at random. what is the probability that it contains a)no 9's? b) at least one 9?

1. 👍 0
2. 👎 0
3. 👁 879
1. There are 9000 numbers from 1000 to 9999 inclusive

then number without any 9 are
8x9x9x9 = 5832

reasoning:
the lead digit has to be
1,2,3,4,5,6,7,8
after that each place can be filled in 9 ways, that is, with
0,1,2,3,4,5,6,7,8

prob (no 9 anywhere) = 5832/9000 = .648

so prob(at least one 9) = 1 - .648 = .352

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Jar Marbles

A jar contains 5 red marbles, numbered 1 to 5, and 12 blue marbles numbered 1 to 12. a) A marble is chosen at random. If you're told the marble is red, what is the probability that it has the number 3 on it? b) The first marble is

2. ### math

-Find the number of distinguishable permutations of the given letters ``AAABBBCCC''. -If a permutation is chosen at random, what is the probability that it begins with at least 2 A's?

3. ### discrete math

Find how many positive integers with exactly four decimal digits, that is, positive integers between 1000 and 9999 inclusive, have the following properties: (a) are divisible by 5 and by 7. (b) have distinct digits. (c) are not

4. ### stat

Problem 2. THE PROBABILITY THAT A RANDOMLY CHOSEN SALES PROSPECT WILL MAKE A PURCHASE IS 0.20. IF A SALESMAN CALLS ON SIX PROSPECTS, A. WHAT IS THE PROBABILITY THAT HE WILL MAKE EXACTLY FOUR SALES? B. WHAT IS THE PROBABILITY THAT

1. ### Statistics Probability

A jar contains 5 red marbles, numbered 1 to 5, and 11 blue marbles numbered 1 to 11. a) A marble is chosen at random. If you're told the marble is red, what is the probability that it has the number 2 on it? b)The first marble is

2. ### Math

A letter from the word MATHEMATICS is chosen at random. What Is the probability that the following letters are chosen S

3. ### Maths

If a number is chosen at random from integers 5 to 25 inclusive, find the probability that the number is (a) multiple of 5 or 3 (b) even or prime number (c) less or greater than 18

4. ### probability;math

A card is chosen at random from a deck of 52 cards It is then replaced and then a second card is chosen.What is the probability of choosing a jack and then an eight?

1. ### math

A bottle contains 12 red marbles and 8 blue marbles. A marble is chosen at random and not replaced. Then, a second marble is chosen at random. Determine the probability that the two marbles are not the same color. Determine the

2. ### math

A two-digit number is chosen at random.What is the probability that the chosen number is a multiple of 7 ? please answer and explain

3. ### Statistics

If a permutation is chosen at random, what is the probability that it begins with at least 2 A's? The probability is

4. ### Maths

Hi, I am just doing some maths revision in light of my maths GCSE resit, which is very soon. I am sitting the higher paper for the first time, so some of the questions towards the end of the paper are very testing of my knowledge.