The rectangle in the figure has dimensions $16$ x $20$ and is divided into $10$ smaller equal rectangles. What is the perimeter of each of the $10$ smaller rectangles?

Consider numbers of the form $1a1$, where $a$ is a digit. How many pairs of such numbers are there such that their sum is also a palindrome? Note: A palindrome is a number which reads the same from left to right and from right to left. Examples: $353$, $91719$.

Tadeo draws the rectangle with the largest perimeter that can be divided into $2015$ squares of sidelength $1$ $cm$ and the rectangle with the smallest perimeter that can be divided into $2015$ squares of sidelength $1$ $cm$. What is the difference between the perimeters of the rectangles Tadeo drew?

We have that $(a+b)^3=216$, where $a$ and $b$ are positive integers such that $a>b$. What are the possible values of $a^2-b^2$?

Camila creates a pattern to write the following numbers: $2, 4$ $5, 7, 9, 11$ $12, 14, 16, 18, 20, 22$ $23, 25, 27, 29, 31, 33, 35, 37$ $…$ Following the same pattern, what is the sum of the numbers in the tenth row?