This week's challenge is to build minesweepers.The test is over two rounds. In round one, each team is given 10 minutes to destroy as many paint-bomb mines as possible in a minefield containing 20 randomly buried mines. The team that destroys the most mines in this round will be given a head-start in the next, with each mine in the winning margin worth five seconds. In round two, each minefield contains just one gigantic mine. Whoever finds the big mine first is the winner.