A magic square is an arrangement of n2 numbers into n rows and n columns using distinct numbers from 1 up to n2 such that the sum in any row, any column or any of the two diagonals is fixed. Consider...

Extracted text: A magic square is an arrangement of n2 numbers into n rows and n columns using distinct numbers from 1 up to n2 such that the sum in any row, any column or any of the two diagonals is fixed. Consider the 4 by 4 magic square below: a1 a5 2 13 a2 10 11 a7 аз 6 а4 12 4 15 a6 1 What is the value of a4 ? O 7 O 5 O 16 O 9