21 foot board long is cut into 3 pieces. second pieces is twice as long as first piece, and 3rd piece is 5 feet longer than the 1st. How long are the 3 pieces?
A carpenter cuts an oak board 21 feet long into 3 pieces. If the second piece is twice as long as the firs piece and the third piece is 5 feet longer than the first piece, how long are the 3 pieces?