Tag Archives: algebra

Radical Radicals

This is another UKMT Senior Challenge problem, but for the year 2005. I thought it was diabolical and hadn’t a clue how to solve it. Even after reading the solution, I don’t think I could have come up with it. I take my hat off to anyone who solves it.

“Which of the following is equal to

Answer.

See Radical Radicals for a solution.

Challenging Sum

Here is a problem from the UKMT Senior (17-18 year-old) Mathematics Challenge for 2009:

“Four positive integers a, b, c, and d are such that

abcd + abc + bcd + cda + dab + ab + bc + cd + da + ac + bd + a + b + c + d = 2009.

What is the value of a + b + c + d?

A 73_________B 75_________C 77_________D 79_________E 81”

Answer.

See the Challenging Sum for a solution.

(Update 4/17/2019) Continue reading