hard Set 81 Form Exercise

Number Chain: 12 → -8 → +10 → x3 → x5 → +5 → ?

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Answer: 215

SubType
number-chain
Start
12
Steps
  • {"op":"-","operand":8}
  • {"op":"+","operand":10}
  • {"op":"x","operand":3}
  • {"op":"x","operand":5}
  • {"op":"+","operand":5}
Difficulty
hard

Number Chain: 2 → x5 → +8 → +1 → +9 → x3 → ?

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Answer: 84

SubType
number-chain
Start
2
Steps
  • {"op":"x","operand":5}
  • {"op":"+","operand":8}
  • {"op":"+","operand":1}
  • {"op":"+","operand":9}
  • {"op":"x","operand":3}
Difficulty
hard

Number Chain: 1 → x5 → +5 → x2 → x4 → -9 → ?

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Answer: 71

SubType
number-chain
Start
1
Steps
  • {"op":"x","operand":5}
  • {"op":"+","operand":5}
  • {"op":"x","operand":2}
  • {"op":"x","operand":4}
  • {"op":"-","operand":9}
Difficulty
hard

Number Chain: 6 → x2 → +5 → -16 → +5 → -5 → ?

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Answer: 1

SubType
number-chain
Start
6
Steps
  • {"op":"x","operand":2}
  • {"op":"+","operand":5}
  • {"op":"-","operand":16}
  • {"op":"+","operand":5}
  • {"op":"-","operand":5}
Difficulty
hard

Number Chain: 7 → +9 → +10 → -11 → -7 → x2 → ?

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Answer: 16

SubType
number-chain
Start
7
Steps
  • {"op":"+","operand":9}
  • {"op":"+","operand":10}
  • {"op":"-","operand":11}
  • {"op":"-","operand":7}
  • {"op":"x","operand":2}
Difficulty
hard

Number Chain: 7 → +5 → +2 → x5 → x4 → x3 → ?

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Answer: 840

SubType
number-chain
Start
7
Steps
  • {"op":"+","operand":5}
  • {"op":"+","operand":2}
  • {"op":"x","operand":5}
  • {"op":"x","operand":4}
  • {"op":"x","operand":3}
Difficulty
hard

Number Chain: 9 → +6 → +10 → +12 → -19 → -11 → ?

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Answer: 7

SubType
number-chain
Start
9
Steps
  • {"op":"+","operand":6}
  • {"op":"+","operand":10}
  • {"op":"+","operand":12}
  • {"op":"-","operand":19}
  • {"op":"-","operand":11}
Difficulty
hard

Number Chain: 2 → x5 → x4 → +7 → +1 → x3 → ?

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Answer: 144

SubType
number-chain
Start
2
Steps
  • {"op":"x","operand":5}
  • {"op":"x","operand":4}
  • {"op":"+","operand":7}
  • {"op":"+","operand":1}
  • {"op":"x","operand":3}
Difficulty
hard