Answer: It can be seen that the numbers in the 3rd pentagon (from left to right) are the difference between the numbers in the 2nd and 1st pentagon (according to each position). In other words, subtracting the number in hexagon 2 from the number in the corresponding position in hexagon 1 will equal the number in hexagon 3 according to the position of the previous 2 shapes.
We have: 5 – 2 = 3 (the difference between 2 and 5 is 3 units)
5- 4 = 1 (the difference between 5 and 4 is 1 unit)
11 – 6 = 5 (the difference between 11 and 6 is 5 units)
9 – 7 = 2 (the difference between 9 and 7 is 2 units)
So we can deduce that the number we are looking for is 10 because 10 – 1 = 9 (the difference between 10 and 1 is 9 units)
