Permutations and Combinations
How many four digit numbers that are divisible by can be formed using the digits to if no digit is to occur more than once in any number?
Correct Answer: Option(b)
We need to find digit numbers that are divisible by contain numbers to
Since the number is to be divisible by the last digits can only be one of the following:
For set There are possible ways for last digits. For the first digit cannot be used and also the digits already used for last digits. So we have choices for digit and then again remaining choices for digit.
For set Last digits can be chosen from possibilities. First digits can be chosen from remaining numbers.
Hence, the answer is