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23 Hours and Counting!

The United Kingdom has a television show called Countdown (see web site 1 or web site 2). The game is similar to the classic classroom game called Krypto; I have seen only part of a foreign rip-off of it. Yet, the program first aired on November 2nd, 1982...and has been running 5 days a week at 3:30 pm each afternoon for 34 years.

Part of the program asks contestants to calculate a given number by adding, subtracting, multiplying and dividing using a series of whole numbers. For example, if asked to calculate 999 using the numbers 5, 2, 1 and 100, one solution would be (2 * 5) * 100 - 1 = 999. Are there others?

One problem took the program's consulting mathematics expert 23 hours to solve. Usually, she takes less than a minute for most of the problems that arise on the show. Can you work it out?

The Problem: Make the number 261 using the numbers 6, 6, 4, 2, 10 and 100.

Remember that you can only use each number the number of times it appears. That is, you can use the number 6 twice but all of the other numbers only once.

Finally, if you want to practice, a special Countdown link on a recreational website exists as well.


Hint: Sorry...do not have one. You now have 22 hours plus and counting!


Solution Commentary: If you find an expression that works, send it to me and I will record it here. I expect that more than one successful expression exists.

The one solution (that I am aware of) was discovered by someone named Paul in less than 15 minutes: 4 x [100 - (6 x 6)] + 10/2 = 261.