Question

How many two-digit counting numbers do not contain any of the digits 1, 3, or 9?

42 numbers

72 numbers

81 numbers

49 numbers

Answer #1

Two-digit number,

case 1. we can not include 0, 1 3 9 then remaining number if 2,4,5,6,7,8

the number of remaining numbers is 6, with the help of 6 numbers we can create 6*6=36 possible number of two-digit.

without zero 36 numbers are possible.

case 2. take zero and fixed it at first digit,

....0

remaining one digit fill by 2,4,5,6,7,8,

6 possible way (20,40,50,60,70,80)

(02,04, is not a two-digit number. it is a single-digit number)

in this case, we get 6 possible ways.

The total possible number is (6+36)=42

discrete math counting problem
How many positive 4 digit numbers ( using digits 1-9) that
contain at least one 1 and at least one 2 are there?

Counting theory: Find how many 4-digit positive
integers are there with no repeating digits (e.g.: 5823) or where
digit repetition is allowed but all digits must be odd (e.g.: 5531
satisfies this condition but 7726 and 6695 do not since they
contain even digits).

How many string of four decimal digits do not contain the same
digit three times?
How many string of five decimal digits do not contain the same
digit three times?

How many 4-digit numbers can be formed from the digits 2, 3, 8
and 9?

How many four-digit numbers can be formed from the digits 1,
3, 5, 7, 8, and 9 if the numbers are less than 3,000 and digits are
not used repeatedly? ( Hint: Begin with the digit where there is a
restriction on the choices.)

How many diffrent two-digit numbers can you use the
digits 4,3,7,1,2,6, and 9 without repetition? For example, 77 is
not allowed
The number of diffrent two-digit number is

how
many four digit numbers can be formed from digits 1, 3, 5, 7 ,8 and
9.; if the numbers are less than 3000 th digits are not used
repeadetly.

Six-digit numbers are to be formed using only the digits in the
set:
A = {1, 2, 3, 4, 5, 6, 7, 8}
How many such numbers can be formed if repetitions of the
digits are allowed?
In part (a), how many of the numbers contain at least one 3 and
at least one 5?
c. How many 6-digit numbers can be formed if each digit in A can
be used at most once?

In Sydney, phone numbers at present consist of eight digits,
starting with the digit 9.
i. How many phone numbers are possible?
ii. How many of these end in an odd number?
iii. How many consist of odd digits only?
iv. How many are there that do not contain a zero, and in which
the consecutive digits alternate between odd and even?
Please provide full working and correct answer .

How many possible 5 digit numbers can be formed with the 10
digits 0 to 9 if repetitions are not allowed and zero cannot be the
first digit?

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 3 minutes ago

asked 20 minutes ago

asked 38 minutes ago

asked 52 minutes ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 3 hours ago

asked 3 hours ago

asked 3 hours ago

asked 3 hours ago