Syvum Home Page

Home > Math Puzzles & Brain Teasers > Print Preview

Math Puzzles & Brain Teasers


Unique Numbers

View Puzzle Solve Puzzle

Hide all answers   View all answers   Print   Try the Quiz

There is a number that is 6 times the sum of its digits. What is this number?
Answer: 54

Solution:

The number is 54, simply because
54 = 6 (5 + 4).

How does one find this number?

Let t be the digit in the tens place and u be the digit in the units place. Then, the number is 10 t + u, and the sum of its digits is t + u. The following equation can be readily written:

10 t + u = 6 t + 6 u or
4 t = 5 u.

Thus, t / u = 5 / 4. Since t and u are digits, t must be 5 and u must be 4.

Food for thought:

Is the assumption of a 2-digit number a valid one?

  Try the Quiz :     Puzzles & Brain Teasers : Unique Numbers


Contact Info © 1999-2022 Syvum Technologies Inc. Privacy Policy Disclaimer and Copyright
Previous
-
Next
-