The elevator in Jack's building supports a maximum load of 700 kg. An adult weighs an average of 80 kg. If Jack rides the elevator with 8 other adults, by how much will they have exceeded the maximum load of the elevator?
Jack and 8 other adults form a total of 8 adults + 1 adult = <<8+1=9>>9 adults.
In total, the 9 adults together weigh 9 adults * 80 kg/adult = <<9*80=720>>720 kg.
They have exceeded the maximum load of the elevator by 720 kg - 700 kg = <<720-700=20>>20 kg.
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