 # Solved for 42: long-lasting math problem finally gets its answer

Here’s a problem which sounds simple enough, but isn’t: find three numbers so that the sum of their cubes is equal to 42. A planetary scientist just solved the problem, and the numbers will definitely surprise you.

The original problem was laid out in 1954 at the University of Cambridge, and was very straightforward: find the solutions for x3+y3+z3=k, with k being all the numbers from one to 100. Some of them are pretty obvious. Just take 1, 2, and 3, sum their cubes, and you end up with 1+8+27=36 — so you have an answer to 36. You can be a bit clever and use -1 instead of 1, which leaves you with -1+8+27=34, and you have another solution. After you take out all these easy solutions, you’re left with some weird ones though.

There should be a solution for all numbers, but two proved particularly different to crack: 33 and 42. Thanks to a creative approach (and a week at a world-leading supercomputer), Professor Andrew Booker managed to solve it for 33. Coincidence or not, the only remaining number was 42 — which fans of the Hitchhiker’s Guide to the Galaxy will recognize as “the answer to Everything”, according to a fictional computing machine that worked for 7 million years.

Booker tried to solve the equation for 42, but couldn’t — so he turned to MIT maths professor Andrew Sutherland. Together, the two used a machine that’s surprisingly similar to the fictional one described above. The platform is called Charity Engine: a ‘worldwide computer’ that harnesses idle, unused computing power from over 500,000 home PCs to create a crowd-sourced, super-green platform made entirely from otherwise wasted capacity. It didn’t take 7 million years, but it did take quite a long time. Yet, at the end of it all, the two had their answer.

The three numbers for which the sum of their cubes is equal to 42 are:

• X = -80538738812075974
• Y = 80435758145817515
• Z = 12602123297335631

These three incredibly large numbers are the solution to the problem — trust us, we did the math. 