Answer keyBack-rank mates11... Rd1#Black to move21... Rb1#Black to move31... Qf1+ 2. Rxf1 Rxf1#Black to move41. Qxd8+ Rxd8 2. Rxd8#White to move51. Qxf7+ Kh8 2. Qf8+ Rxf8 3. Rxf8#White to move61... Qxf2+ 2. Kh1 Qf1+ 3. Rxf1 Rxf1#Black to moveSolve these on screen at chessboost.orgPage 2