Proper Patterns

Given some of the proper factors of a number, what could the number be?

Partial Sum of Consecutive Integers

Can a partial sum of consecutive positive integers equal a number with identical digits?

Hypatia’s Triumph

Take on the Egyptian Hypatia’s challenge about sums of squares.

Double Trouble

Find a number that fits this description.

Sum of Infinite Fractions

Determine the sum of an infinite geometric series that begins with the number one.

The Frog Race

Two frogs have a race. Determine which frog wins the race.

Perfecting 90

How can 90 become a perfect square? a perfect cube?

Three Daughters

Determine the age of each daughter.

Multiples of 72

What is the relationship between two divisors and their product, sum, difference, and quotient?

Choose an Elevator

Determine which of two elevators reaches the lobby first.