The Missing Number Puzzle | Logic game for adults and kids with its answer

 The Missing Number Puzzle

Question :

You are given a list of numbers from 1 to 100, but one number is missing. The numbers are randomly ordered. Your task is to find the missing number.

Here's the catch: you can only use the sum formula to find the missing number, and you must do it in less than a minute.

How can you find the missing number?

Solution:

1. Calculate the sum of all numbers from 1 to 100: You can use the formula for the sum of an arithmetic series: $\text{Sum}=\frac{𝑛}{2}\times (𝑎+𝑙)$, where $𝑛$ is the number of terms, $𝑎$ is the first term, and $𝑙$ is the last term. In this case, $𝑛=100$, $𝑎=1$, and $𝑙=100$. So, $\text{Sum}=\frac{100}{2}\times (1+100)=50\times 101=5050$.
2. Find the sum of the numbers in the list: Add up all the numbers in the list.
3. Subtract the sum of the numbers in the list from the sum of all numbers from 1 to 100: Subtract the sum found in step 2 from 5050.
4. The result is the missing number: The difference between 5050 and the sum of the numbers in the list is the missing number.

This method allows you to find the missing number efficiently without having to individually examine each number in the list.