Figure shows an equilateral triangle of side of length 5 which is divided into several unit triangles. A valid path is a path from the triangle in the top row to the middle triangle in the bottom row such that the adjacent triangles in our path share a common edge and the path never travels up (from a lower row to a higher row) or revisits a triangle. An example is given below. How many such valid paths are there?

• given side length=5 .....so (n-1)!=(5-1)!=4!
  ans is 24
• 9 years agoHelpfull: Yes(9) No(1)
• 24 such paths are possible.
  
• 9 years agoHelpfull: Yes(2) No(1)
• how to solve this logically
• 8 years agoHelpfull: Yes(0) No(1)