Question 9
The puzzle below is composed of circles and arrows. A dashed arrow indicates addition, while a solid arrow indicates multiplication. For example, the solution to the diagram on the left is a number whose sum is $5+9$, which is $14$. The solution to the diagram on the right is a number that, when multiplied by $6$, gives us $12$, which by working backwards, leads us to a solution of $2$. Note that there could be more than $2$ arrows pointing to a circle, in which case there is one operation (addition or multiplication) with more than $2$ numbers involved.
In the following puzzle below, if all the circles must contain positive integers, what number must be placed in the circle with the question mark?
In the following puzzle below, if all the circles must contain positive integers, what number must be placed in the circle with the question mark?