## Crack the Hidden Code of Missing Number Puzzle to Test Your Pattern Identification and Math Reasoning Skills

Spot the rule to crack the code in the missing number puzzle. The puzzle is good for growing minds as it tests their quick pattern identification skills.

### The Missing number Puzzle with 2 in one of 5 equations

If,

** 2 = 3**

** 4 = 15**

** 7 = 48**

** 11 = 121**

Then,

** 9 = ???**

You have good logical thinking skills if you spot the hidden operation in each equation and crack the code in 1 minute's time. **This is a one-minute puzzle.**

### How to crack the hidden code of the missing number puzzle with 2 in one of 5 equations: Step by step logical approach

#### Property analysis of the missing number puzzle

- 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 5 is 5).**The key lies in an operation on the left hand side of each equation.**

#### Focus is on the left hand side part: Logic Analysis and Math Reasoning

**Math logic says,**

- The
**right side numbers increase uniformly as well as the left side single numbers**, but the**rate of increase is much faster on the right side**. **Conclusion:****Multiplying the left side number by a single number is out of question**,*because in first equation, 2 increases just by 1 and in fourth 11 increases by 109.*

#### Finding the hidden operation on the left side number and crack the code

Eliminating the option of multiplying the left side number by a single multiplier (or even by an increasing multiplier), **the best option left is to square the left side number and see how it turns out.**

**Equation 1:** 2 = 3 => 2x2 - 1 = 3

**Equation 2:** 4 = 15 => 4x4 - 1 = 15

**Equation 3:** 7 = 48 => 7x7 - 1 = 48

**Equation 4:** 11 = 120 => 11x11 -1 = 120.

The **easily discovered rule is to square the left side number**, as considered, and **subtract 1 to get the result.** *The rule holds for all four equations.*

**Solution:** 9 => 9x9 -1= **80**.

Even though it is easy to crack the code,

it is good for growing minds.It will give them an opportunity to test their pattern identification skill which is vital in any type of problem solving.

*Easy puzzles also their uses.*

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