245 Why does multiplying a number on a clock face by 10 and then halving, give the minutes? ${}{}$ 89 Why do you add +1 in counting test questions? 52 What is the probability of the sum of four dice being 22? 33 Why is it that if I count years from 2011 to 2014 as intervals I get 3 years, but if I count each year separately I get 4 years? 32 A certain car model costs 21,000 euro now, and it devaluates 5% every year. How much will it cost in 6 years?

### Reputation (27,700)

 +10 Showing $p \mid 16x^4 + 1 \implies p \equiv 1 \pmod 4$ +10 Is there a difference between one or two lines depicting the norm? +10 How to find probabilty? +10 Open unit disc is homeomorphic to sphere minus a point

### Questions (50)

 28 Continued fraction with prime reciprocal entries 20 Will every rational number eventually be in this set? 16 Explicit bijection between $\Bbb R$ and permutations of $\Bbb N$ 14 Factoring rational primes over the Eisenstein integers - when can a prime be written as $j^2+3k^2$? 12 Application of Taylor's Theorem in Number Theory

### Tags (283)

 290 combinatorics × 54 162 elementary-number-theory × 71 254 algorithms × 6 142 arithmetic × 13 235 probability × 63 109 real-analysis × 45 214 algebra-precalculus × 69 100 elementary-set-theory × 33 172 calculus × 94 90 limits × 29