Pick a Number
This number trick was proposed as a mathematical “sticker” that hosts could share over dessert.
Take a number, multiply it by 5, add 6, multiply by 4, add 9 to the product, multiply the sum by 5, and tell the result. I will tell you your number.
Question: How did the host determine the original number?
Solution:
Source: Leonardo Fibonacci, Italy, 1200
