Question 504407
Let 
Length of first piece = x

Given
Length of Board = 56 inches
Length of Second piece = 2x
Length of third piece = 4x

Total length of three pieces = Length of Board
x+2x+4x=56
7x=56
x=56/7
x=8


Length of first piece = 8 inches
Length of Second piece = 16 inches
Length of third piece = 32 inches