Acarpenter has several boards of equal length. he cuts 3/4 of each board. after cutting the boards, the carpenter notices that he has enough pieces left over to make up the same length as 4 of the original boards. how many boards did the carpenter start with?

Let us assume the number of boards that the carpenter started with = x
Length of each board that the carpenter cuts = 3/5
Then
x - 3x/5 = 4
(5x - 3x)/5 = 4
2x/5 = 4
2x = 4 * 5
2x = 20
x = 20/2
   = 10
So from the above deduction, we can conclude that the carpenter started with 10 boards.I hope the procedure is not that complicated and it is easy for you to understand.