[Njtechdiv] Excel formulas

[Mario Brusco]

using Excel, I have created a workbook with an increasing number of 
spreadsheets. I have simplifyed an example to demonstrate my request:

I need a formula to retrieve the last entry in a column, but aren't able 
to figure out how to compose a formula that works as expected. I'd 
appreciate if someone can help write it.

for sheet1, sheet 2, sheet3, etc:

column a is formatted with a type of general, column b is formatted with 
a type of number, column c is formatted with a type of date.
cells 2, 4 and 6 of each column contain different data respective of 
their format type.
the last cell of each column contains a formula that simply retrieves 
the last entry in that column. the range of cells that it should 
reference is a2:a9.

a2= Mary. b2= 23. c2=4/21/2017.
the cells in row 3 of each column is left empty.
a4= Frank. b4= 18. c4= 5/5/2016.
the cells in row 5 of each column is left empty.
a6= Paul. b6= 32. c6= 8/3/2018.
the remaining cells of each column are left blank.
a10= the formula to retrieve the name Paul. b10= the formula to retrieve 
the number 32. c10= the formula to retrieve the date 8/3/2018.
if any of the columns are left blank, a10, b10 or c10 should also be 
left blank, not a 0 or an error.
and the cells on the summary sheet that reference either a10, b10 or c10 
should also remain blank

the summary sheet simply retrieves the last cells of each column in the 
other spreadsheets in the workbook. the formula would be =sheet1!a10 or 
=sheet2!b10, =sheet3!c10, etc.

a1= =sheet1!a10. b1= =sheet1!b10. c1= =sheet1!c10.
a2= =sheet2!a10. b2= =sheet2!b10. c2= =sheet2!c10.
a3= =sheet3!a10. b3= =sheet3!b10. c3= =sheet3!c10.
etc. etc. etc.

I think one formula needs to be written to handle string values and 
another formula to handle number values. any questions, pleas reply.