# Posted in September 2012 …

## #math trivia solution: Each day there’s a 20% chance that a given class has a quiz. …

#math trivia: Each day there’s a 20% chance that a given class has a quiz. What’s the chance that at least one of the five classes does? — Burt Kaliski Jr. (@modulomathy) September 25, 2012 To determine the chances that something happens at least once, it’s often easiest to figure out the probability p that … Continue reading

## #math trivia solution: The five classes eat lunch at separate times …

#math trivia: The five classes eat lunch at separate times. Every day their times are in a different order. How long can this go on? — Burt Kaliski Jr. (@modulomathy) September 17, 2012 There are 5*4*3*2*1 = 120 different possible orders in which the five classes can eat lunch, so this can go on for … Continue reading

## #math trivia solution: The 20-student class gets the flu …

#math trivia: The 20-student class gets the flu. Every day a different prime number of students is out sick. For how long can this go on? — Burt Kaliski Jr. (@modulomathy) September 10, 2012 There are eight different prime numbers less than or equal to 20 (2, 3, 5, 7, 11, 13, 17 and 19), … Continue reading

## #math trivia solution: Two friends got in the same class …

#math trivia: The two friends got in the same class. Seats are assigned randomly, 4 rows of 5. What are the chances that they sit together? — Burt Kaliski Jr. (@modulomathy) September 3, 2012 The chances that the two friends are seated next to each other is 8/95.  This can be calculated as follows: The … Continue reading

## A Universe of Amazing Science and Technology

The most recent and sophisticated of the number space probes sent from Earth to Mars landed on the Red Planet five weeks ago, continuing a remarkable record of exploration of our fascinating neighbor. While most of Earth has been mapped out (at least the parts on land), Mars and the rest of the multi-billion-light-year vast … Continue reading

## #math trivia solution: 100 students are assigned randomly …

#math trivia: 100 students are assigned randomly to 5 classes of equal size. What are the chances that two friends get in the same class? — Burt Kaliski Jr. (@modulomathy) August 28, 2012 The chances that two friends get in the same class is 19 out of 99. If the classes didn’t have to be … Continue reading