Question 6
What number should replace the question mark? Each group has a top number, a left number, a right number and a bottom number, and a centre number: top 7, left 24, right 6, bottom 9 gives 28; top 14, left 9, right 8, bottom 4 gives 27; top 16, left 9, right 10, bottom 11 gives ?. Answer with a natural number.