Question

The number of different seven digit numbers that can be formed by 1,2,3,4,3,2,1

Answer 1

Answer:

The answer is 630

Step-by-step explanation:

Number of ways is found out by using permutations.

Number of common 1s = 2

Number of common 2s = 2

Number of common 3s = 2

So number of ways=7!/(2!*2!*2!) = 630