1. Choose a number between 1 and 100.

2. Multiply the number by 5.
3. Add 15 to the number.
4. Divide the number by 5.
5. Subtract the original number.
How does this work, please help!

i dont know why this works could someone help?

1. Choose a number between 1 and 100. ------> x

2. Multiply the number by 5. -------> 5x
3. Add 15 to the number. -------> 5x+15
4. Divide the number by 5. ------> x+3
5. Subtract the original number. ------> 3

try it with any number:
1. ----- 12
2. ------ 60
3. ------ 75
4. ------ 15
5. ------ 3

My dad taught me this trick when I was about 15 but WARNED me that to make it work the number you multiply and divide it by must be the same. There must be some other caveats too.

Let's go through each step to understand how this process works.

1. Choose a number between 1 and 100. Let's say you chose the number 10.
2. Multiply the number by 5. 10 multiplied by 5 gives you 50.
3. Add 15 to the number. Adding 15 to 50 gives you 65.
4. Divide the number by 5. 65 divided by 5 gives you 13.
5. Subtract the original number. Subtracting 10 from 13 gives you 3.

The final result is 3.

Now, let's see how this process works for any number, not just 10. We can call the chosen number 'n' and follow the same steps.

1. Choose a number 'n' between 1 and 100.
2. Multiply the number 'n' by 5. This gives you 5n.
3. Add 15 to the number. This gives you 5n + 15.
4. Divide the number by 5. This gives you (5n + 15)/5 = n + 3.
5. Subtract the original number. Subtracting 'n' from (n + 3) gives you 3.

So no matter what number you choose, following these steps will always result in 3. This is because the steps involve basic mathematical operations that essentially cancel each other out, leaving you with 3 as the final result.