Answer:
It is not valid
Step-by-step explanation:
I'll assume the question relates to cell referencing in Microsoft Excel.
To reference a cell in Excel, we make use of the following steps:
- Write out the cell column name first
- Followed by the row number
7b implies that, the row number first, followed by the column name; this doesn't follow the naming convention of cells.
Hence, 7b is invalid.