Riddles with matrices

Puzzles, riddles, brain teasers, conundrums, logic questions in pictures. Here all tasks are presented in the form of various matrices. Most often these are rectangular matrices that have external rows and columns. In these logic puzzles, brain teasers and conundrums, the columns and rows affect the contents of the matrices. To check your answer, click on the «Answer» button located below the task. After this, the correct answer and explanations will appear. Below you can select other questions on this topic. Typically each topic has 20 questions or more. At the same time, the complexity of logical problems gradually increases. First there will be easy questions, then medium, then difficult. Try to complete tasks as quickly as possible.
Question - 9
This is a logic riddle with a circular matrix of numbers in a sense. You need to figure out the number placement rule and choose the correct number from the answer options below to replace the question mark.
Correct answer = 7.
There are two ring lines with numbers. The sum of any two nearest numbers in the outer ring is equal to the sum of any two nearest numbers in the inner ring. Below in the image circles circle groups of numbers with equal amounts in different rings.
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