Question 9
I make a multiplication table for the numbers from 1 to 5. What is the sum of the 25 numbers inside this table? Each interior entry is the product of its row and column labels. The source table is blank for these entries.
|$\times$|1|2|3|4|5|
|---|---|---|---|---|---|
|1||||||
|2||||||
|3||||||
|4||||||
|5||||||
|$\times$|1|2|3|4|5|
|---|---|---|---|---|---|
|1||||||
|2||||||
|3||||||
|4||||||
|5||||||