Saturday, August 19, 2017

Factor Sums


Not counting itself, the number 6 has the factors 1, 2, and 3, which add to 6. The number 28 has the same property (its factors are 1, 2, 4, 7, and 14). Can you come up with a three-digit number that has this property? What about a four-digit number? Click below for the answers.


Saturday, August 12, 2017

Minimum Percentage


75% of men from a certain group are tall, 75% have brown hair, and 75% have brown eyes. What is the minimum percentage that are tall, have brown hair, and have brown eyes? Click below to see the answer.


Saturday, August 5, 2017

A Two-Digit Number


Find a two-digit number that's equal to two times the result of multiplying its digits. Click below to see the answer.