### Number 143 of a continuing series

#### I’ve been riding on airplanes again, and I lifted this problem from the American Way magazine, courtesy of Mensa.

This isn’t a geometry puzzle. It’s a problem in mathematical logic. There is a simple logic used for the first three triangles to determine the number on the inside by applying the logic to the numbers at the vertices. Use that same logic for the fourth triangle to determine the missing number inside the triangle.

## Update and solution

Yes, this really was a hard one. What you had to do was to figure out the logic that was consistent with the first three triangles. And not just any logic, but the simplest logic. And that simple logic is:

- Ignore the number at the top and left vertices of the triangle.
- Multiply the number at the right vertex by 6 to get the number in the middle.

The answer is, of course, 48.