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Solve the Missing Number Puzzle with 5 Equations

Missing Number Puzzle with 5 Equations

Crack the Hidden Code of Missing Number Puzzle to Test Your Logical and Analytical Thinking

Spot the hidden key to crack the code in the missing number puzzle. Logic analysis, hidden pattern discovery and math reasoning are the key skills tested.

This type of puzzles test your inventive thinking skill as well. After all, inventive thinking is: ability to discover possibilities that are not easy to get hold of.

The Missing number Puzzle including 24 with a well-hidden key

   23 + 4 = 24

   21 + 5 = 20

   34 + 6 = 48

   41 + 2 = 12

   52 + 7 = ???

You have good logical thinking skills if you spot the hidden operation in each equation and crack the code in 2 minute's time.

Solution to the missing number puzzle with 5 equations: Step by step logical approach

Property of the missing number puzzle: Analysis

  • One rule must satisfy each equation.
  • The digits are not coded, otherwise there would have been more variables than equations making the puzzle unsolvable.
  • Conclusion: each digit in the equations is the actual face value of the digit (for example, 2 is 2 and 6 is 6).
  • The key lies in an operation on the left hand side of each equation.

Focus is on the left hand side part of an equation: Logic Analysis

Logic says,

  • Usually the arithmetic operations are not tinkered with. For example a + symbol means addition. We assume this is so in this puzzle as well, and go ahead to find the solution.
  • The result on the right side of an equation should be the actual value of the number.
  • But, the two digit number on the left side may not represent the actual value of the number. Let us be flexible and treat each digit of the number on the left individually.
  • Conclusion: The key operation must be hidden in the two digit number and the single digit term on the left of an equation.

Taking up the first equation, ask yourself the key question, what operation on digits 2, 3 of 23 and number 4 added can produce the result of 24?

The answer seems to be not straightforward.

Finding the key operation to crack the code

A rule that works for the first equation:

  • The result 24 is six numbers of 4.
  • Adding 2 and 3 makes 5, multiply with the second term 4. Result is 20. Add with 4 as in per the equation. Result 24.
  • The + operation is used in the usual way, but an additional product operation is introduced between the two terms.

This might be the key rule that forms all the other results.

Checking the other three equations: Solution

   21 + 5 = 20 : (2+1)x5 + 5 = 20

   34 + 6 = 48 : (3+4)x6 + 6 = 48

   41 + 2 = 12 : (4+1)x2 + 2 = 12

The rule works for each equation.

Solution: 52 + 7 => (5+2)x 7 + 7=56.

Combine logical thinking with Systematic approach, and you would get the solution with confidence.


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