Question Id : 13184 |
Context : JEE Main 2023 (24 January Evening Shift)
The number of square matrices of order 5 with entries from the set {0,1}, such that the sum of all the elements in each row is 1 and the sum of all the elements in each column is also 1, is:
🎥 Video solution / Text Solution of this question is given below:
Key Insight: Each row has exactly one $1$ and rest $0$s. Each column also has exactly one $1$ and rest $0$s.
So no two rows can have $1$ in the same column. This is exactly a Permutation Matrix!