Question 16
Esther and Frida are supposed to fill a rectangular array of $16$ columns and $10$ rows with the numbers $1$ to $160$. Esther does it row-wise: the first row is $1,2,\ldots,16$, the second is $17,18,\ldots,32$, and so on. Frida does it column-wise: the first column is $1,2,\ldots,10$, the second is $11,12,\ldots,20$, and so on. Some numbers occupy the same position in both arrays. Find the sum of the numbers in these positions.
