Posted in April 2012 …

#math trivia #55 solution

#math trivia for #February24: #55 is the 10th in the series 1 1 2 3 5 8 13 21 34 55. What’s the 11th and what’s the series? — Burt Kaliski Jr. (@modulomathy) February 24, 2012 The next term is 89, and the series is the Fibonacci Series. New terms follow a simple rule:  They’re … Continue reading

#math trivia #54 solution

#math trivia for #February23: #54 is halfway between a #cube and a #square, two different ways.  What are they?  (Positive numbers only.) — Burt Kaliski Jr. (@modulomathy) February 23, 2012 One solution is 27 (= 33) and 81 (= 92). The other is 8 (=23) and 100 (=102). The problem can be solved by trial … Continue reading

#math trivia #53 solution

#math trivia for #February22: #53 is surrounded by more composites than any prime so far.  How many immediate neighbors of 53 aren’t prime? — Burt Kaliski Jr. (@modulomathy) February 22, 2012 Ten immediate neighbors of 53 aren’t prime: 48 49 50 51 52 … 54 55 56 57 58 The gaps between 47 and 53 … Continue reading

#math trivia #52 solution

#math trivia for #February21: Day #52 — 1/7th of the way through the year. Whenwill it be 1/6th? — Burt Kaliski Jr. (@modulomathy) February 21, 2012 An easy one today:  One sixth of the way through a 366-day leap year is exactly 61 days, a milestone reached on March 1. In a non-leap year, the … Continue reading

#math trivia #51 solution

#math trivia for #February20: #51 is 33 base 16. Approximately what fraction is 33 base 16 of 100 base 16? — Burt Kaliski Jr. (@modulomathy) February 20, 2012 33 is just under one third of 100 base 10 — but the question is asking about base 16. There are two approaches to solve this one.   … Continue reading

#math trivia #50 solution

#math trivia for #February19: #50 is the largest “coin” dividing into a 100-unit “dollar”. What are the other “coins” for this “dollar”? — Burt Kaliski Jr. (@modulomathy) February 19, 2012 For the purposes of this problem, a “coin” should be taken as a a divisor of 100 that is smaller than 100.  Even though 100 … Continue reading

#math trivia #49 solution

#math trivia for #February18: #49 is the first composite that Eratosthenes sieves with a prime other than 2, 3 or 5. What’s the next one? — Burt Kaliski Jr. (@modulomathy) February 18, 2012 The Sieve of Eratosthenes is an ancient algorithm for separating prime numbers from composites.  Suppose we want to find all the primes … Continue reading