Question

This is not a correct approach and should never be followed (turn into simple sentence)​​​

Answer 1

Explanation:

A seven digit number has to be formed using 1,2,3 (and not necessarily all of them) with 1 never immediately followed by 2, 2 never immediately followed by 3 and 3 never immediately followed by 1. The number of such numbers equals0

Answer 2

we should never follow approaches