#math trivia #46 solution

#math trivia for #February15: 46 is a nontrivial (multi-digit) palindrome in base 4 (46 = 232 base 4) and which four other bases? — Burt Kaliski Jr. (@modulomathy) February 15, 2012 A positive integer x can be expressed in any base b ≥ 2 as a sum of weighted powers x = dk-1 bk-1 + dk-2 bk-2 … Continue reading →

#math trivia #45 solution

#math trivia for #February14: 45 is the 9th triangular number: 45 = 1+2+3+…+9. How do you make a 9×9 square out of 45-unit triangles? — Burt Kaliski Jr. (@modulomathy) February 15, 2012 The nth triangular number has the form 1+2+3+…+n, and is so named because it measures the “units” in a triangularly shaped figure with … Continue reading →

#math trivia #44 solution

#math trivia for #February13: 44 is the fifth number of the form p^2*q for distinct primes p, q. What are p and q? What were the first four? — Burt Kaliski Jr. (@modulomathy) February 13, 2012 Factoring the day’s number, 44, quickly yields the values of p and q: 44 = 2^2 * 11 , … Continue reading →

#math trivia #43 solution

#math trivia for #February12:43 is the smallest number of form p^4+q^3 where p, q are prime. What are p and q? What’s the next number? — Burt Kaliski Jr. (@modulomathy) February 12, 2012 This is a quick one.  If 43 is the smallest number of the given form, then p, having the larger exponent, must be the smallest … Continue reading →

#math trivia #42 solution

#math trivia for #February11:42 is the second smallest tricomposite:42 = 2*3*7; what are its eight divisors? — Burt Kaliski Jr. (@modulomathy) February 11, 2012 Tricomposite is not in the dictionary, but its definition should be clear from context:  a tricomposite number is the product of three primes.  Bicomposite numbers are common in cryptography — the … Continue reading →

Surely You’re Joking

For my birthday this year, my sister gave me a copy of Surely You’re Joking, Mr. Feynman. In Part 1, subtitled “From Far Rockaway to MIT,” the famous physicist describes how at age 11 or 12 he built his own electrical circuit with lamps and switches. At around the same age, I built a circuit … Continue reading →

Hello world!

Welcome to WordPress.com. After you read this, you should delete and write your own post, with a new title above. Or hit Add New on the left (of the admin dashboard) to start a fresh post. Here are some suggestions for your first post. You can find new ideas for what to blog about by … Continue reading →