# Tag: math

1. ## Space Race

Another FiveThirtyEight Riddler.The President has bestowed upon you 1 billion dollars with the mission of getting us to an alien artifact as fast as possible! Here's whats available to you: Big Russian engines costing 400 million each. Buying one will reduce the trip time by 200 days. Buying two…

2. ## Impossible Puzzle

Another weekly FiveThirtyEight riddler, and this one's a mind-bender. Three very skilled logicians are sitting around a table — Barack, Pete and Susan. Barack says: “I’m thinking of two natural numbers between 1 and 9, inclusive. I’ve written the product of these two numbers on this paper that I’…

3. ## Casino Game

The solution for this weeks FiveThirtyEight riddler is pretty nutty. The riddle is essentially: If you drew random numbers from a uniform distribution from [0,1], what is the expected number of draws you would perform until their sum exceeds 1? So let us define $S_{n}$ as the sum…

4. ## 1 + 2 + 3 + ...

Here's something mind-blowing: If you take the sum of the first couple of natural numbers you get the triangle numbers: $$T_{1} = 1$$ $$T_{2} = 1 + 2$$ $$T_{3} = 1 + 2 + 3$$ $$T_{n} = (n)(n-1)/2$$ So essentially the series 1 + 2 + 3 + 4 + ... is the area of an…

on math