0
We have three cases:
1- Hundreds digit= Tens digit:
In every hundred 9 numbers are in this pattern:
110-112-113-114-115-116-117-118-119
and we have 9 hundreds, so in this case there are 81 numbers.
2- Hundreds digit= Units digit:
In every hundred 9 numbers are in this pattern:
101-121-131-141-151-161-171-181-191
and we have 9 hundreds, so in this case there are 81 numbers!
3- Tens digit= Units digit:
In every hundred 9 digits are in this pattern:
100-122-133-144-155-166-177-188-199,
and we have 9 hundreds, so in this case there are 81 numbers!
Total = 81 + 81 + 81 = 243
Oh, dude, let me break it down for you. So, there are 9 choices for the digit that's different from the other two, and 3 choices for where that different digit goes. That gives us 27 possible numbers with exactly 2 digits the same. Easy peasy, lemon squeezy.
To find the number of 3-digit numbers with exactly 2 digits the same, we can break it down into cases. There are 9 choices for the repeated digit (1-9, excluding 0), 8 choices for the non-repeated digit, and 3 positions for the non-repeated digit in the number (hundreds, tens, or units place). Therefore, the total number of such numbers is 9 * 8 * 3 = 216.
Answer is 243
Starting at 100 (the first 3-digit number), I counted all numbers that had exactly two digits that were the same. I did this through 199. There are 27 of these. I then multiplied that result by 9 (to pick up the 200s through 900s).
Add your answer:
Earn +20 pts
How many 6 digit numbers contain exactly different 4 digits?
There are 22680 numbers, excluding those with leading 0s.
How many 5 digits numbers are there whose digits sum to 22?
There are 5460 five digit numbers with a digit sum of 22.
How many whole numbers have exactly four digits?
how many numbers exactly have 4 digits ? 8900, 8999, 9000, 9999
How many even two digit numbers are there where the sum of the digits is 5?
To find the even two-digit numbers where the sum of the digits is 5, we need to consider the possible combinations of digits. The digits that sum up to 5 are (1,4) and (2,3). For the numbers to be even, the units digit must be 4, so the possible numbers are 14 and 34. Therefore, there are 2 even two-digit numbers where the sum of the digits is 5.
How many 6 digit numbers can be formed using the digits 123456789?
There are 60480 numbers.
How many 3-digit numbers have exactly 2 digits that are the same?
1
How many 3 digit numbers have 2 of the same digits?
Exactly 2: 243 of them.
How many four digit numbers are there which have exactly the same two digits.?
Any pair of digits (not including 0), can be used to generate 14 four-digit numbers. If one of the digits is 0, only seven will start with a non-zero digit.
How many 6 digit numbers contain exactly different 4 digits?
There are 22680 numbers, excluding those with leading 0s.
How many 1 digit numbers can make with 123 digits?
With 123 digits you can make 123 one-digit numbers.
How many 5 digits numbers are there whose digits sum to 22?
There are 5460 five digit numbers with a digit sum of 22.
How many 6 digit numbers contain exactly 4 digits?
Zero; all six digit numbers have six digits. Dude.. i m asking 6 digit numbers, containing only 4 different digits..!! e.g.:123412.. with only 2 digits repeated..!! My guess is: 10*9*8*7*4*3 but I'm also guessing that is wrong- sorry!
How many whole numbers have exactly four digits?
how many numbers exactly have 4 digits ? 8900, 8999, 9000, 9999
How many 3 digit numbers can be formed from the digits 357 with any digit repeated?
27 three digit numbers from the digits 3, 5, 7 including repetitions.
How many 4 digit numbers can be formed from digits 123456789?
There are 7,290 different 4-digit numbers that can be formed from the digits 1-9 without repetition.
How many two digit whole numbers are increased by 18 when their digits are reversed?
7 two-digit numbers.
How many 4 digit numbers have 6 as their second digit?
There are 9 digits that can be the first digit (1-9); for each of these there is 1 digit that can be the second digit (6); for each of these there are 10 digits that can be the third digit (0-9); for each of these there are 10 digits that can be the fourth digit (0-9). → number of numbers is 9 × 1 × 10 × 10 = 900 such numbers.
