The numbered net is folded into a cube. Three faces meet at the corner marked by the orange dot. What is the sum of the numbers on those three faces?

The dot is the lower-left corner of 3. When the lower row is rolled round, the bottom edge of 3 closes up against the bottom edge of 1, and the dot lands where the bottom edges of 1 and 5 meet. So 3, 1 and 5 meet at that corner: $3+1+5=9$. (11 adds 3, 6 and 2, the squares next to the dot in the flat net, but 3 and 2 are opposite.)