First find the number of inches in each flight of stairs: 12 steps * 8 inches/step = <<12*8=96>>96 inches
Then find the net number of flights of stairs Jack went down: 6 flights - 3 flights = <<6-3=3>>3 flights
Then multiply than number by the number of inches per flight to find how many inches further down he is: 96 inches/flight * 3 flights = <<96*3=288>>288 inches
Then divide that number by 12 to find the number of feet down he is: 288 inches / 12 inches/foot = <<288/12=24>>24 feet
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