Final answer:
Upon cutting 3/5 of each board, the carpenter finds that the leftover pieces amount to the length of 4 original boards. Calculating the equation (2/5)x = 4 and solving for x, we find out that the carpenter originally had 10 boards.
Step-by-step explanation:
The question involves determining the original number of boards a carpenter had before cutting them and noticing that the leftover pieces equaled the length of 4 original boards. We know that the carpenter cuts 3/5 of each board, meaning that 2/5 of each board is leftover. If the leftovers equate to 4 whole boards, we can set up an equation to solve for the original number of boards (let's call this number 'x').
Since 2/5 of each board is leftover, and the leftovers make 4 full boards, we can represent this situation with the equation (2/5)x = 4. To solve for 'x', we divide both sides of the equation by 2/5 which is equivalent to multiplying by its reciprocal (5/2), yielding x = 4 × (5/2) = 10. Therefore, the carpenter started with 10 boards.