There are 2941 4-digit numbers such no two of its digits differ by 1.
what is the least possible sum of two 4-digit numbers?what is the least possible sum of two 4-digit numbers?
3 digit numbers are lessthan 4 digit numbers
Add the two greatest possible four digit numbers. 9999 + 9999
Highest 2-digit number = 99 Highest 1-digit number = 9 Highest possible sum from 2, 2-digit numbers = 198 Highest possible sum from 2, 1-digit numbers = 18
5
The first digit can have 5 possible numbers, the second digit can have 4, the third 3, the fourth 2. 5
There are 900 three digit numbers. (99 - 1000) (# of possible numbers in the first position = 9) (# of possible numbers in the second position = 10) (# of possible numbers in the third position = 10) 9 *10 *10 = 900
There are 30,240 different 5-digit numbers. Math: 10*9*8*7*6 1st digit has 10 possible choices (0-9) 2nd digit has 9 possible choices (one of the digits was used in the 1st digit) 3rd digit has 8 possible choices 4th digit has 7 possible choices 5th digit has 6 possible choices
625 if numbers can have leading 0s, 500 otherwise.
Without repeats there are 4 × 3 = 12 possible 2 digit numbers. With repeats there are 4 × 4 = 16 possible 2 digit numbers.
There are 4 possible numbers if the digits are not repeated; 18 if they are. Those are 3-digit numbers, assuming that zero would not be a leading digit. If zero is allowed for a leading digit, then you can have 6 for the non repeated, and 27 if repetition.
There are 16 4-digit numbers that can be made up from 9 and 6.